<PAGE>   1
                                 UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON, DC 20549

                                   FORM 10-Q


   [X]  QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
        EXCHANGE ACT OF 1934

        For the quarterly period ended June 30, 1998

                                       OR

   [ ]  TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
        EXCHANGE ACT OF 1934

        For the transition period from                   to 
                                       ----------------     ----------------

                        Commission File Number 000-21267

                            SUMMIT BANK CORPORATION
             (Exact name of Registrant as specified in its charter)


                    GEORGIA                      58-1722476
              (State or other jurisdiction of  (IRS Employer
              incorporation or organization)   Identification No.)

                          4360 Chamblee-Dunwoody Road
                             Atlanta, Georgia 30341
          (Address of principal executive offices, including Zip Code)

                                 (770) 454-0400
              (Registrant's telephone number, including area code)

      Indicate by check mark whether the Registrant (1) has filed all reports
 required to be filed by Section 13 or 15(d) of the Securities Exchange Act of
 1934 during the preceding 12 months (or for such shorter period that the
 Registrant was required to file such reports), and (2) has been subject to
 such filing requirements for the past 90 days.

      Yes   X                                         No  
           ---                                            ---

                     APPLICABLE ONLY TO CORPORATE ISSUERS:

      Indicate the number of shares outstanding of each of the issuer's classes
 of capital stock, as of the latest practicable date.

<TABLE>
<CAPTION>
         Class                               Outstanding at August 1, 1998
         -----                               -----------------------------
 <S>                                         <C>      
 Common Stock. $.0l par value                          1,815,363
</TABLE>

                      The Exhibit Index Appears on Page 15



                                  Page 1 of 19


<PAGE>   2




                         PART I. FINANCIAL INFORMATION

ITEM 1. FINANCIAL STATEMENTS
SUMMIT BANK CORPORATION AND SUBSIDIARIES
CONDENSED CONSOLIDATED BALANCE SHEETS
(Unaudited)


<TABLE>
<CAPTION>
                                                             June 30,      December 31,
(In thousands)                                                 1998           1997
---------------------------------------------------------------------------------------
<S>                                                          <C>           <C>

ASSETS:
Cash and due from banks                                      $  14,272       $   8,091
Federal funds sold                                              15,725           1,200
Interest-bearing deposits in other banks                           394              69
Investment securities available for sale, at fair value         79,004          61,396
Other investments                                                1,314           1,566
Loans, net of unearned income                                  119,812          95,473
Loans held for sale                                              2,531           3,419
Less:  allowance for loan losses                                (2,796)         (1,468)
--------------------------------------------------------------------------------------
      Net loans                                                119,547          97,424
--------------------------------------------------------------------------------------
Premises and equipment, net                                      4,493           4,461
Customers' acceptance liability                                  1,826           1,397
Deferred income taxes                                              208             134
Goodwill                                                         3,261              --
Other assets                                                     4,088           4,558
--------------------------------------------------------------------------------------
      Total assets                                           $ 244,132       $ 180,296
======================================================================================

LIABILITIES AND STOCKHOLDERS' EQUITY
LIABILITIES:
Deposits:
   Non-interest-bearing demand                               $  41,840       $  35,193
   Interest-bearing:
      Demand                                                    39,805          34,348
      Savings                                                    8,665           6,681
      Time, $100,000 and over                                   34,455          23,595
      Other time                                                76,629          44,978
--------------------------------------------------------------------------------------
      Total deposits                                           201,394         144,795
--------------------------------------------------------------------------------------

Obligation under capital lease                                      60              81
Federal Home Loan Bank advance                                  10,000          10,000
Other borrowed funds                                             5,009           2,756
Acceptances outstanding                                          1,826           1,397
Other liabilities                                                2,012           1,489
--------------------------------------------------------------------------------------
      Total liabilities                                        220,301         160,518
--------------------------------------------------------------------------------------

STOCKHOLDERS' EQUITY:
   Common stock                                                     18              15
   Additional paid-in capital                                   16,178          12,933
   Retained earnings                                             7,569           6,658
   Accumulated other comprehensive income                           66             172
--------------------------------------------------------------------------------------
      Total stockholders' equity                                23,831          19,778
--------------------------------------------------------------------------------------

      Total liabilities and stockholders' equity             $ 244,132       $ 180,296
======================================================================================
</TABLE>


See Accompanying Notes to Condensed Consolidated Financial Statements.


                                  Page 2 of 19


<PAGE>   3



SUMMIT BANK CORPORATION AND SUBSIDIARIES
CONDENSED CONSOLIDATED INCOME STATEMENTS
(Unaudited)




<TABLE>
<CAPTION>
                                                          Three months                      Six months
                                                          ended June 30,                    ended June 30,
(Dollars in thousands, except share 
and per share amounts)                                 1998              1997            1998            1997
---------------------------------------------------------------------------------------------------------------
<S>                                                  <C>             <C>             <C>             <C>       
Interest income
    Loans, including fees                            $    2,678      $    2,387      $    5,267      $    4,727
    Interest-bearing deposits in other banks                  4               1               6               2
    Federal funds sold                                       85              23             167             152
    Investment securities-taxable                           401             345             810             571
    Mortgage-backed securities                              634             556           1,238           1,060
---------------------------------------------------------------------------------------------------------------
       Total interest income                              3,802           3,312           7,488           6,512
---------------------------------------------------------------------------------------------------------------

Interest expense
    Time deposits, $100,000 and over                        385             361             758             657
    Other deposits                                        1,023             875           1,983           1,773
    Federal Home Loan Bank advance                          124              61             250              66
    Short-term borrowings and obligation
       under capital lease                                   44              36              78              52
---------------------------------------------------------------------------------------------------------------
       Total interest expense                             1,576           1,333           3,069           2,548
---------------------------------------------------------------------------------------------------------------

       Net interest income                                2,226           1,979           4,419           3,964
Provision for loan losses                                   195             135             355             260
---------------------------------------------------------------------------------------------------------------
       Net interest income after provision
        for loan losses                                   2,031           1,844           4,064           3,704
---------------------------------------------------------------------------------------------------------------

Non-interest income
    Fees for international banking services                 292             321             576             568
    SBA loan servicing fees                                  61             111             137             222
    Service charge income                                    74              68             147             126
    Overdraft and NSF charges                               159             100             290             210
    Gains on sales of loans                                 216             208             373             208
    Net gains on sales of investment securities              31              19              48              19
    Other                                                   108              95             221             174
---------------------------------------------------------------------------------------------------------------
       Total non-interest income                            941             922           1,792           1,527
---------------------------------------------------------------------------------------------------------------

Non-interest expenses
    Salaries and employee benefits                          985             896           1,969           1,812
    Equipment                                               195             153             342             307
    Net occupancy                                           139             128             278             250
    Other operating expenses                                693             617           1,340           1,242
---------------------------------------------------------------------------------------------------------------
       Total non-interest expenses                        2,012           1,794           3,929           3,611
---------------------------------------------------------------------------------------------------------------
    Income before income taxes                              960             972           1,927           1,620
---------------------------------------------------------------------------------------------------------------
Income tax expense                                          341             314             683             551
---------------------------------------------------------------------------------------------------------------
    Net income                                       $      619      $      658      $    1,244      $    1,069
---------------------------------------------------------------------------------------------------------------
Basic net income per common share                    $      .34      $      .47      $      .72      $      .76
Diluted net income per common share and
    common share equivalents                         $      .34      $      .40      $      .69      $      .65
---------------------------------------------------------------------------------------------------------------
Weighted-average shares outstanding - basic           1,815,363       1,408,126       1,735,086       1,407,908
Weighted-average shares outstanding - diluted         1,821,161       1,633,243       1,802,091       1,639,677
---------------------------------------------------------------------------------------------------------------
Dividends declared per common share                  $      .10      $      .09      $      .19      $      .17
===============================================================================================================
</TABLE>


See Accompanying Notes to Condensed Consolidated Financial Statements.

                                  Page 3 of 19


<PAGE>   4




SUMMIT BANK CORPORATION AND SUBSIDIARIES
CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS
(Unaudited)

<TABLE>
<CAPTION>
                                                                                             Six months
                                                                                           ended June 30,
(In thousands)                                                                           1998           1997
--------------------------------------------------------------------------------------------------------------
<S>                                                                                  <C>            <C>     
Cash flows from operating activities:

Net income                                                                           $  1,244       $  1,069
Adjustments to reconcile net income to net cash
 provided by operating activities:
  Depreciation and amortization of premises and equipment                                 214            159
  Net amortization of premiums/discounts on
    investment securities                                                                  49             41
  Amortization of negative goodwill                                                       (55)           (55)
  Provision for loan losses                                                               355            260
  Gains on sales of loans                                                                (373)          (208)
  Net gains on sales of investment securities                                             (48)           (19)
Changes in other assets and liabilities:
  Decrease (increase) in other assets                                                   1,054           (648)
  Increase in other liabilities                                                           246             80
------------------------------------------------------------------------------------------------------------
  Net cash provided by operating activities                                             2,686            679
------------------------------------------------------------------------------------------------------------

Cash flows from investing activities:

Proceeds from maturities of investment securities available for sale                   11,260          1,000
Principal collections on investment securities available for sale                       4,616          2,543
Proceeds from sales of investment securities available for sale                         2,855         13,966
Purchases of investment securities available for sale                                 (22,311)       (32,010)
Loans made to customers, net of principal collected on loans                           (2,973)        (7,411)
Purchases of premises and equipment                                                      (172)           (34)
Purchase of California Security Bank, net of cash and cash equivalents acquired          (320)            --
------------------------------------------------------------------------------------------------------------
  Net cash used in investing activities                                                (7,045)       (21,946)
------------------------------------------------------------------------------------------------------------

Cash flows from financing activities:

Net increase (decrease) in demand and savings deposits                                  1,598         (5,368)
Net increase in time deposits                                                          18,645          3,951
Principal payments for obligation under capital lease                                     (21)           (18)
Dividends paid                                                                           (333)          (239)
Issuance of common stock upon exercise of warrants and options                          3,248             --
Net increase in borrowed funds                                                          2,253          8,071
------------------------------------------------------------------------------------------------------------
  Net cash provided by financing activities                                            25,390          6,432
------------------------------------------------------------------------------------------------------------

Net increase (decrease) in cash and cash equivalents                                   21,031        (14,835)
Cash and cash equivalents at beginning of period                                        9,360         23,417
------------------------------------------------------------------------------------------------------------
   Cash and cash equivalents at end of period                                        $ 30,391       $  8,582
------------------------------------------------------------------------------------------------------------
   Supplemental disclosures of cash paid during the period:
     Interest                                                                        $  2,908       $  2,245
     Income taxes                                                                    $    831       $    357
------------------------------------------------------------------------------------------------------------
</TABLE>


See Accompanying Notes to Condensed Consolidated Financial Statements.


                                  Page 4 of 19


<PAGE>   5


SUMMIT BANK CORPORATION AND SUBSIDIARIES
NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS
(Unaudited)

1.   BASIS OF PRESENTATION

     The consolidated financial statements included herein have been prepared by
     Summit Bank Corporation and Subsidiaries (the "Company"), without audit,
     pursuant to the rules and regulations of the Securities and Exchange
     Commission. Certain information and footnote disclosures normally included
     in consolidated financial statements prepared in accordance with generally
     accepted accounting principles have been omitted, although the Company
     believes that the disclosures are adequate to make the information
     presented not misleading. In the opinion of management, the information
     furnished in the condensed consolidated financial statements reflects all
     adjustments necessary to present fairly the Company's financial position,
     results of operations and cash flows for such interim periods. Management
     believes that all interim period adjustments are of a normal recurring
     nature. These consolidated financial statements should be read in
     conjunction with the Company's audited financial statements and the notes
     thereto as of December 31, 1997, included in the Company's Annual Report on
     Form 10-K for the fiscal year ended December 31, 1997.

     The consolidated financial statements include the accounts of the Company
     and its wholly owned subsidiaries, The Summit National Bank (the "Bank")
     and The Summit Merchant Banking Corporation (inactive.) All intercompany
     accounts and transactions have been eliminated in consolidation.

2.   ACCOUNTING POLICIES

     Reference is made to the accounting policies of the Company described in
     the notes to consolidated financial statements contained in the Company's
     Annual Report on Form 10-K for the year ended December 31 1997.

3.   ACQUISITION

     On June 30, 1998, the Company acquired all of the issued and outstanding
     common stock of California Security Bank, a single-branch California state
     chartered bank located in San Jose, California, for a cash price of
     $6,193,000, including acquisition costs. The acquisition was recorded by
     the Company under the purchase method of accounting. Goodwill of $3,261,000
     was recorded in connection with the purchase and is being amortized over 20
     years. The fair value of assets acquired and liabilities assumed were as
     follows:

<TABLE>
     <S>                                         <C>
     In thousands                                         
     ------------
     Cash and due from banks                     $  1,845 
     Federal funds sold                             3,835 
     Investment securities available for sale      13,948 
     Loans, net                                    19,132 
     Premises and equipment                            74 
     Other assets                                     786 
     Deposits                                     (36,356)
     Other liabilities                               (332)
                                                 -------- 
     Fair value of net assets acquired              2,932 
                                                 -------- 
     Cash paid to shareholders                      6,000 
     Acquisition costs                                193 
                                                 -------- 
     Total purchase price                           6,193 
                                                 -------- 
     Cost over fair value of net assets acquired $  3,261 
                                                 ======== 
</TABLE>
                                                          
     The net cash paid was $320,000.                      
     









                                  Page 5 of 19


<PAGE>   6

     The following is proforma information for the six months ended June 30,
     1998 and 1997 as if the acquisition had been consummated on January 1, 1998
     and 1997, respectively. The proforma information is not necessarily
     indicative of the combined financial position or results of operations
     which would have been realized had the acquisition been consummated during
     the period or as of the dates for which the proforma financial information
     is presented:


<TABLE>
<CAPTION>
                                                    For the Six Months Ended
                                                    ------------------------
                                              June 30, 1998          June 30, 1997
                                              -------------          -------------
(in thousands, except for per share data)  Historical  Proforma  Historical    Proforma
                                           ----------  --------  ----------    --------

<S>                                        <C>         <C>       <C>           <C>
Net interest income                            $4,419    $5,348       $3,964      $4,798
Provision for loan losses                         355       355          260         260
Non-interest income                             1,793     1,933        1,527       1,653
Non-interest expense                            3,929     4,890        3,611       4,614
Provision for income taxes                        684       684          551         560
Net income                                      1,244     1,352        1,069       1,017
Basic net income per share                        .72       .78          .76         .72
Diluted net income per share                      .69       .75          .65         .62
</TABLE>


4.   ACCOUNTING PRONOUNCEMENTS

     In June 1997, the Financial Accounting Standards Board ("FASB") issued
     Statement of Financial Accounting Standards No. 130, "Reporting
     Comprehensive Income" ("SFAS 130"). This statement establishes standards
     for reporting and displaying of comprehensive income and its components in
     a full set of general purpose financial statements. SFAS 130 requires all
     items that are required to be recognized under accounting standards as
     components of comprehensive income be reported in an annual financial
     statement that is displayed in equal prominence with the other annual
     financial statements. For interim period financial statements, enterprises
     are required to disclose a total for comprehensive income in those
     financial statements. The term "comprehensive income" is used in SFAS 130
     to describe the total of all components of comprehensive income including
     net income. "Other comprehensive income" refers to revenues, expenses,
     gains, and losses that are included in comprehensive income but excluded
     from earnings under current accounting standards. Currently, "other
     comprehensive income" for the Company consists solely of items previously
     recorded as a component of stockholders' equity under SFAS 115, "Accounting
     for Certain Investments in Debt and Equity Securities". The Company has
     adopted the interim-period disclosure requirements of SFAS 130 effective
     January 1, 1998 and will adopt the annual financial statement reporting and
     disclosure requirements of SFAS 130 effective December 31 1998.

     Total comprehensive income for the three months and six months ended June
     30, 1998 was $516,000 and $1,138,000 compared to $826,000 and $1,041,000
     for the three months and six months ended June 30, 1997.

     In June 1997, the FASB issued Statement of Financial Accounting Standards
     No. 131, "Disclosures about Segments of an Enterprise and Related
     Information" ("SFAS 131"). SFAS 131 is effective for financial statements
     for years beginning after December 15, 1997. The Company does not have any
     separate segments that are considered material.

     In June 1998, the FASB issued Statement of Financial Accounting Standards
     No. 133, "Accounting for Derivative Instruments and Hedging Activities"
     ("SFAS 133"). SFAS 133 is effective for financial statements for fiscal
     quarters beginning after June 15, 1999. The Company has not made an
     assessment on the expected impact that SFAS 133 will have on its financial
     statements.

5.   RECLASSIFICATIONS

     Certain 1997 amounts have been reclassified for comparative purposes in
     order to conform the prior period to the 1998 presentation.






                                  Page 6 of 19


<PAGE>   7


ITEM 2.   MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND
          RESULTS OF OPERATIONS

Performance Overview

Summit Bank Corporation and Subsidiaries (collectively, the "Company") reported
net income of $619,000 for the second quarter of 1998 compared to earnings for
the same period last year of $658,000. The earnings decrease is attributable to
slightly higher non-interest expenses in second quarter 1998 as well as an
increased effective tax rate. Net earnings per share for second quarter 1998
were $.34 (diluted) as compared to $.40 (diluted) for second quarter 1997. Basic
earnings per share for the respective second quarters of 1998 and 1997 were $.34
and $.47. Current year to date net income through June 30 was $1,244,000, a 16%
increase over 1997 year to date earnings of $1,069,000. Diluted earnings per
share for the six-month periods of 1998 and 1997 were $.69 and $.65,
respectively while basic earnings per share for the same periods were $.72 and
$.76, respectively. The annualized return on average stockholders' equity for
the 1998 six-month period was 11.1% versus 12.4% for the 1997 six-month period,
while the returns on average assets for the comparable periods were 1.31% and
1.35%. Book value per share was $13.13 at June 30, 1998 compared to $13.28 at
December 30, 1997 and $12.59 at June 30, 1997. The decline in earnings per share
and return on average shareholders' equity in 1998 year to date compared to the
same period in 1997 was mainly due to the issuance of an additional 408,000
shares of common stock resulting from the exercise of organizers' warrants
issued in 1988 and stock options issued during the Company's first ten years of
operations. In second quarter 1998, the Company paid a dividend of $.10 per
share to its shareholders.

On June 30, 1998, the Company acquired a financial institution, California
Security Bank, in San Jose, California for a cash price of $6 million by merging
California Security Bank into The Summit National Bank. The acquisition was
accounted for using the purchase method of accounting. The acquired bank had one
office location and total assets of $40 million, which included investment
securities of $14 million and loans of $19 million at June 30. Primarily due to
this addition, total assets for the Company at June 30, 1998 increased to $244
million, an increase of 51% during the last twelve months and 35% since year-end
1997. Total loans were $122 million at June 30 compared to $99 million at
year-end 1997, an increase of 24%. Total deposits have grown $70 million, or
53%, during the last twelve months and $57 million, or 39%, since December 31,
1997. The acquisition contributed $36 million of deposits to the Company's
deposit base, $6 million of which were non-interest-bearing deposits. The
Company's subsidiary Bank experienced a strong growth in time deposits due to a
special 10- and 20-month Certificate of Deposit promotion held in second quarter
1998. During second quarter, the influx of time deposits added $15 million of
funds for investment in loans and securities, in addition to providing cash for
the acquisition.

Net interest income increased 12% to $2.2 million during second quarter 1998
compared to the same period in 1997, primarily due to a higher volume of
interest earning assets. For the six-month periods of 1998 and 1997, net
interest income increased 11% to $4.4 million. The Company's net interest margin
through June 30, 1998 declined to 5.13% from 5.57% for the comparable period in
1997 due primarily to a higher cost of funds. In addition, yields on
interest-earning assets have declined slightly from 9.0% for the six months
ended June 30, 1997 to 8.7% for the same period in 1998 due to lower yields on
investment securities purchased to replace called agency securities and slightly
lower rates on loans as a result of increased competition.

The provision for loan losses increased to $195,000 from $135,000 for the
respective second quarters of 1998 and 1997 due to loan volume growth in 1998.
Gross charged off loans for the quarter ended June 30, 1998 were $17,000 while
recoveries for the period were $169,000, resulting in an annualized net recovery
rate of .20% of total loans for the current year to date compared to an
annualized net charge-off rate for the year to date 1997 of .96% The recoveries
recorded in second quarter included $47,000 of guaranteed portions of SBA loans
previously charged-off. Net loan charge-offs were 1.08% of total loans for the
year ended December 31, 1997.

Non-interest income was relatively flat from second quarter 1998 to second
quarter 1997. Gains on sales of SBA loans for second quarter 1998 and 1997 were
$216,000 and $208,000, respectively. Increases in service charge income and
overdraft fees of $65,000 comparing second quarter 1998 to the same period in
1997 were partially offset by a decline in SBA loan servicing fees of $50,000.
The increase in service charge fees were a result of higher demand deposit
volumes and an increase in service charge rates effected in May, 1997. The
decline in SBA loan servicing fees was due in part to the decrease in servicing
rates received on sold loans as a result of heightened competition over the past
year, in addition to the increase in the offsetting amortization expense of the
related servicing asset. Year to date non-interest income was $1.8 million, a
17% increase over 1997 to date non-interest

                                  Page 7 of 19


<PAGE>   8

income. This increase was primarily due to the sale of SBA loans in first
quarter 1998 while no SBA loans were sold in first quarter 1997.

Non-interest expenses increased $218,000, or 12%, in the second quarter of 1998
as compared to the same period last year. A portion of the increase was due to
the costs allocated to ensure that the Bank is ready for Year 2000 within the
time frame set by the Office of the Comptroller of the Currency. In second
quarter, $45,000 was earmarked for this cause, and the Bank completed the task
of assessment and replacement of computer hardware to Year 2000 compliant
equipment. Personnel costs of $985,000 also increased from second quarter 1997
by $89,000 primarily due to salary increases, higher temporary employee expenses
and SBA loan commission expenses. Other operating expenses increased $76,000, or
12%, to $693,000 for second quarter 1998 compared to the same quarter last year.
General Bank growth and stronger marketing efforts have increased expenses for
data and item processing by $28,000 and marketing costs by $19,000 comparing
second quarter 1998 to the same period in 1997. In addition, miscellaneous
expenses, which include employee relations and incentives and bank security,
increased in second quarter by $23,000 as compared to second quarter last year.
The Company's efficiency ratio for the three-month period of 1998 was 64%,
somewhat higher than the ratio for the same period last year of 62%, primarily
due to the increase in non-interest expenses. Year to date non-interest expenses
increased 9% from 1997 to the current year total of $3.9 million. The increase
was primarily due to higher personnel costs and other operating expenses such as
non-capitalizable equipment (for Year 2000 costs), data processing, marketing
and legal fees.

The financial institution in San Jose that was purchased at June 30, 1998 is
located in leased space in an area of San Jose whose population is predominately
Vietnamese and Chinese. Because of its location, the Company will be able to
capitalize on its major Atlanta strengths in the small business banking arena,
as well as servicing ethnic groups familiar to Summit and providing
international trade finance services to the San Jose market. The San Jose
financial institution, prior to acquisition, was making a small monthly profit.
The Company plans to consolidate most of the back-room operations of the office
with the head office in Atlanta, thus allowing for significant cost savings, and
to operate the San Jose office as a branch of the Bank. With these cost savings
and the addition of several new products and services currently offered to its
Atlanta market, such as cash management services, a voice response system and
international trade finance services, the Company expects this branch office to
make a positive impact on late 1998 earnings.

Asset Quality

Non-performing assets increased to $2,696,000 at June 30, 1998 compared to
$1,777,000 at year-end 1997. Non-performing assets represented 2.20% of total
loans as of June 30, 1998 compared to 1.80% at December 31, 1997. The
acquisition of California Security Bank resulted in the addition of $999,000 of
non-performing loans which consist of two commercial loans, one of which has
been restructured, both collateralized with first mortgages on real estate.
Other non-performing loans at June 30, 1998 represents four fully guaranteed SBA
credits, one real estate credit of $722,000 for which the Bank believes it is
well secured, and one commercial credit also collateralized with first and
second mortgages on real property. One of the SBA credits included in
non-accrual loans at December 31, 1997 was reclassified in January 1998 as a
restructured loan because of interest rate, term, and collateral modifications.
Management believes the restructuring of the loan has enhanced its
collectibility even though the loan will remain non-performing. Additionally,
the loan is fully guaranteed by the SBA.





                                  Page 8 of 19


<PAGE>   9


                             NON-PERFORMING ASSETS


<TABLE>
<CAPTION>
                                                          June 30,     December 31,
 (Dollars in thousands)                                     1998           1997
-----------------------------------------------------------------------------------
<S>                                                       <C>          <C>   
 Loans on non-accrual
     SBA guaranteed                                        $  361         $1,018
     Non-SBA guaranteed                                     1,438            759

 Other real estate                                             --             --

 Restructured loans -
     SBA guaranteed                                           413             --
     Non-SBA guaranteed                                       484             --
--------------------------------------------------------------------------------

    Total non-performing assets                            $2,696         $1,777
--------------------------------------------------------------------------------

 Loans 90 days past due and still accruing interest        $   --             --

 Total non-performing assets as a
    percentage of total loans and ORE                        2.20%          1.80%

 Loans ninety days past due and still accruing
    interest as a percentage of total loans                    --%            --%
</TABLE>


The allowance for loan losses increased to $2,796,000 at June 30, 1998 from
$1,468,000 at year-end 1997, an increase of 90%.  The acquisition of California
Security Bank contributed to the addition of $814,000 to the Company's loan
loss allowance.  Loan losses have also declined this year to date with gross
charge-offs of $202,000 offset by recoveries of $361,000, resulting in a net
annualized charge-off rate of -.20% of average total loans compared to 1.08%
for the entire year of 1997.  The allowance for loan losses represented 2.29%
and 1.48%, respectively, of total loans outstanding at June 30, 1998 and
December 31, 1997.

            ANALYSIS OF ALLOWANCE FOR LOAN LOSSES AT JUNE 30,  1998


<TABLE>
<CAPTION>
       (In thousands)
       -----------------------------------------------------------------
       <S>                                                        <C>
       Allowance for loan losses at December 31,  1997            $1,468

       -----------------------------------------------------------------
       Charge-offs:
       Commercial, financial, and agricultural                       125
       SBA                                                            38
       Real estate                                                    --
       Installment loans to individuals                               39
       -----------------------------------------------------------------

         Total                                                       202
       -----------------------------------------------------------------
       Recoveries:
         Commercial, financial, and agricultural                     115
         SBA                                                         230
         Real estate                                                  --
         Installment loans to individuals                             16
       -----------------------------------------------------------------

             Total                                                   361
       -----------------------------------------------------------------

             Net recoveries                                         (159)
       -----------------------------------------------------------------

       Provision for loan losses charged to income                   355
       Adjustment due to acquisition of California Security Bank     814
       -----------------------------------------------------------------

       Allowance for loan losses at June 30, 1998                 $2,796
       -----------------------------------------------------------------
</TABLE>



                                  Page 9 of 19


<PAGE>   10


The loan portfolio is periodically reviewed to evaluate the outstanding loans
and to measure both the performance of the portfolio and the adequacy of the
allowance for loan losses. This analysis includes a review of delinquency
trends, actual losses and internal credit ratings. Based on this analysis,
management considers the allowance for loan losses at June 30, 1998 to be
adequate to cover loan losses in the portfolio as of that date. However, because
of the inherent uncertainty of assumptions made during the evaluation process,
there can be no assurance that loan losses in future periods will not exceed the
allowance for loan losses or that additional allocations to the allowance will
not be required.

Liquidity and Capital Adequacy

Liquidity has increased in second quarter primarily due to the California
acquisition as compared to December 31, 1997. At June 30, 1998, the Company's
average net loan to deposit ratio was 59%, down from 67% at year end. Management
also analyzes the level of off-balance sheet assets such as unfunded loan
commitments and outstanding letters of credit as they relate to the levels of
cash, cash equivalents, liquid investments, and available federal funds lines to
ensure that no potential shortfall exists. Additionally, the Bank has $16
million of borrowing capacity under a secured line of credit available from the
Federal Home Loan Bank of Atlanta, of which $10 million was being utilized at
June 30, 1998. Based on this analysis, management believes that the Company has
adequate liquidity to meet short-term operational requirements.

Stockholders' equity of the Company increased $4 million to $23.8 million at
June 30, 1998, an increase of 20% from December 31, 1997, and 34% from June 30,
1997. In addition to normal earnings retention, stockholders' equity increased
$3.2 million since December 31, 1997 due to the issuance of common stock from
the exercise of warrants and options. The capital level of the subsidiary Bank
exceeds all prescribed regulatory capital guidelines for adequate
capitalization. Regulations require that the most highly rated banks maintain a
minimum Tier 1 leverage ratio of 3%, and require other banks to maintain a
minimum Tier 1 leverage ratio of 3% plus an additional cushion of at least 1 to
2 percentage points. Tier 1 capital consists of stockholders' equity less
certain intangible assets. The Bank's Tier 1 leverage ratio declined to 7.4% at
June 30, 1998 compared to 9.6% at year end 1997 due to the acquisition. Since it
was a cash transaction, stockholders' equity was not affected while $40 million
in assets were consolidated into the Bank's total assets. Regulations require
that the Bank maintain a minimum total risk weighted capital ratio of 8% with
50%, or 4%, of this amount made up of Tier 1 capital. Risk-weighted assets
consist of balance sheet assets adjusted by risk category and off-balance sheet
asset equivalents similarly adjusted. At June 30, 1998, the Bank had a
risk-weighted total capital ratio of 11.17% and a Tier 1 risk-weighted capital
ratio of 9.91% compared to year-end 1997 ratios of 15.6% and 14.3%,
respectively.

Year 2000

The Company has made significant progress on its Year 2000 compliance project in
1998 in an effort to ensure that failures will not materially adversely affect
its operations. The first major milestone was reached by June 30, 1998 with the
completion of the hardware testing and necessary replacement. The Company
engaged a company to assist in the testing and replacement of any computer
hardware which was not Year 2000 compliant. Actual costs accrued or incurred to
date for this portion of the Year 2000 project are $45,000. A testing plan for
mission critical systems, systems which are necessary to the ongoing operation
of the Bank, is being written, and testing of these systems will begin in
September, 1998. The Company outsources its data processing and item processing
services to third party vendors. The completion of the Company's Year 2000
project and its ability to adequately service its customers in 2000 is largely
dependent on the compliance of these third party vendors. The Company has
monitored the progress of these vendors in their efforts to become Year 2000
compliant over the past year, and will address contingency plans for these
systems in early 1999, if testing has proven unsatisfactory. Another critical
system is utilized in the Bank's international department to process customer
letters of credit and other trade finance products. This system has been
certified as Year 2000 compliant by the third party vendor. The Company also
recognizes the importance of ensuring that borrowers are addressing the problem
in a timely manner to avoid deterioration of the loan portfolio solely due to
Year 2000. The Company has identified all material relationships, mailed
relevent questionnaires to assess the risk, and plans to work with each of these
customers on a one-to-one basis as appropriate to assist them with compliance.
Deposit customer awareness is being addressed through mailings and statement
stuffers.

Accordingly, the Company believes that its internal systems and software and the
network connections it maintains will be adequately programmed to address the
Year 2000 issue. Based on information currently available, management does not
believe that the Company will incur significant additional costs in connection
with the Year 2000 issue. Nevertheless, there can be no assurances that all
hardware and software that the Company will use will be Year 2000 compliant, and
the Company cannot predict with any certainty the costs the Company will incur
to


                                  Page 10 of 19


<PAGE>   11

respond to any Year 2000 issues. Further, since the business of the Company's
customers and vendors may be negatively affected by the Year 2000 issue, any
financial difficulties incurred by the Company's customers and vendors in
solving Year 2000 issues could negatively affect their ability to perform their
agreements with the Company. Therefore, even if the Company does not incur
significant direct costs in connection with responding to the Year 2000 issue,
there can be no assurance that the failure or delay of the Company's customers,
vendors or other third parties in addressing the Year 2000 issue or the costs
involved in such process will not have a material adverse effect on the
Company's business, financial condition and results of operations. 

ITEM 3.   QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK

The Company has not provided quantitative and qualitative disclosures about
market risk as required by Item 305 of Regulation S-K because it met the
requirements of a small business issuer. The Company will be required to provide
this disclosure for the year ended December 31, 1999.

PART II. - OTHER INFORMATION


ITEM 1.   Legal Proceedings - Not Applicable

ITEM 2.   Changes in Securities - Not Applicable

ITEM 3.   Defaults Upon Senior Securities - Not Applicable

ITEM 4.   Submission of Matters to a Vote of Security Holders - Not Applicable

          The 1998 Annual Meeting of the Shareholders (the "Meeting") of the
          Company was held on April 25, 1998. Proxies were solicited prior to
          the meeting from shareholders of record at the close of business on
          March 13, 1997, for the primary purposes of electing six members to
          the Board of Directors and approving the Company's 1998 Stock
          Incentive Plan.

          Article Fourteen of the Company's Amended and Restated Articles of
          Incorporation provides that the Board of Directors shall be divided
          into three classes with each class to be as nearly equal in number as
          possible. Article Fourteen also provides that the three classes of
          directors are to have staggered terms, so that the terms of only
          approximately one-third of the Board will expire at each annual
          meeting of shareholders and each director serves a three-year term.
          Six Class III Directors were nominated at the meeting to serve until
          the Annual Shareholders Meeting in 2001: Gerald L. Allison, Jose
          Gonzalez, James S. Lai, Nack Paek, Carl L. Patrick, Jr., and David Yu.
          All six nominees were elected.

          Proxies for 78%, or 1,423,564 of the 1,815,363 outstanding common
          shares, were received prior to the meeting. A quorum was present by
          proxy. Votes were cast as follows:

<TABLE>
<CAPTION>
                                   Votes            Votes
         Director                  For             Against
         --------                  ---             -------

         <S>                       <C>             <C>   
         Gerald L. Allison         1,412,589        10,975
         Jose Gonzalez             1,416,791         6,773
         James S. Lai              1,422,389         1,175
         Nack Paek                 1,422,589           975
         Carl L. Patrick, Jr.      1,422,589           975
         David Yu                  1,412,589        10,975
</TABLE>

          The following Class I and Class II directors, whose terms did not
          expire at the Annual Shareholders Meeting, continued to serve as
          directors following the meeting: Peter M. Cohen, Donald R. Harkleroad,
          Daniel T. Huang, Shafik H. Ladha, Paul C. Y. Chu, Cecil M. Phillips,
          Howard H. L. Tai, P. Carl Unger, Aaron I. Alembik, Jack N. Halpern,
          Sion Nyen (Francis) Lai, Shih Chien (Raymond) Lo, W. Clayton Sparrow,
          Jr., and Pin Pin Chau.

                                 Page 11 of 19


<PAGE>   12


          The Company's 1998 Stock Incentive Plan was approved with 1,076,239
          votes for, 9,552 votes against, and 4,125 votes abstaining.

          Pursuant to Rule 14a-4(c)(1) promulgated under the Securities Exchange
          Act of 1934, as amended, shareholders desiring to present a proposal
          for consideration at the Company's 1999 Annual Meeting of Shareholders
          must notify the Company in writing at its principal office at 4360
          Chamblee Dunwoody Road, Atlanta, Georgia, 30341 of the contents of
          such proposal no later than February 15, 1999. Failure to timely
          submit such a proposal will enable the proxies appointed by management
          to exercise their discretionary voting authority when the proposal is
          raised at the Annual Meeting of Shareholders without any discussion of
          the matter in the proxy statement.

ITEM 5.   Other Information - None

ITEM 6.   Exhibits and Reports on Form 8-K

          a) Exhibits

<TABLE>
<CAPTION>
          Exhibit
          Number                             Exhibit

          <S>  <C>                                                    
          2.1  Agreement and plan of merger by and between the Summit National
               Bank and California Security Bank, dated March 27, 1998
               (incorporated by reference to Exhibit 2.1 to the Company's
               current report on Form 8-K dated April7, 1998.)

          3.1  Amended and Restated Articles of Incorporation of Summit Bank
               Corporation (incorporated by reference to Exhibit 3.2 of Summit
               Bank Corporation's Registration Statement on Form S-1, Amendment
               No.3 (Registration Number 33-16366.)

          3.2  Bylaws of Summit Bank Corporation, as amended (incorporated by
               reference to Exhibit 3.2 to the Company's Annual Report on Form
               10-K for the fiscal year ended December 31, 1987.)

          4.1  The rights of security holders are defined in (i) Articles Five,
               Six, Nine, Ten, Eleven, Thirteen, Fourteen, and Sixteen of the
               Amended and Restated Articles of Incorporation of Summit Bank
               Corporation and (ii) Articles Two, Three, Eight, Ten, and Eleven
               of the amended Bylaws of Summit Bank Corporation, (incorporated
               by reference to Exhibits 3.1 and 3.2 respectively, to the
               Company's Annual Report on Form 10-K for the year ended December
               31, 1994.)

          10.1 Summit Bank Corporation 1987 Key Employee Incentive Stock Option
               Plan, as amended and restated as of February 28, 1989
               (incorporated by reference to Exhibit 10.1 to the Company's
               Annual Report on Form 10-K for the fiscal year ended December 31,
               1991.)

          10.2 Form of Summit Bank Corporation Organizer's Warrant Agreement
               (incorporated by reference to Exhibit 10.4 of Summit Bank
               Corporation's Registration Statement on Form S-1 (Registration
               Number 33-16366.)

          10.3 Lease Agreement dated December 3, 1993, between Baker Dennard
               Co., Lessor, and Summit National Bank, Lessee (incorporated by
               reference to Exhibit 10.4 to the Company's Annual Report on Form
               10-K for the fiscal year ended December 31, 1993.)

          10.4 Lease agreement dated June 16, 1995, between ZML-Paces Limited
               Partnership, Lessor and Summit National Bank, Lessee
               (incorporated by reference to Exhibit 10.6 to the Company's
               Annual Report on Form 10-K for the fiscal year ended December 31,
               1995.)
</TABLE>



                                  Page 12 of 19


<PAGE>   13
<TABLE>
       <S>    <C>
       10.5   Change in Control Agreement dated August 25, 1995 by and between
              Pin Pin Chau, President of the Summit National Bank, and the
              Summit National Bank (incorporated by reference to Exhibit 10.7 to
              the Company's Annual Report on Form 10-K for the fiscal year ended
              December 31, 1995.)

       10.6   Change in Control Agreement dated August 25, 1995 by and between
              David Yu, Chairman of the Summit National Bank, and the Summit
              National Bank (incorporated by reference to Exhibit 10.8 to the
              Company's Annual Report on Form 10-K for the fiscal year ended
              December 31, 1995.)

       10.7   Change in Control Agreement dated August 25, 1995 by and between
              Alec Dudley, Executive Vice President of the Summit National Bank,
              and the Summit National Bank (incorporated by reference to Exhibit
              10.9 to the Company's Annual Report on Form 10-K for the fiscal
              year ended December 31, 1995.)

       10.8   Change in Control Agreement dated August 25, 1995 by and between
              Gary K. McClung, Executive Vice President of the Summit National
              Bank, and the Summit National Bank (incorporated by reference to
              Exhibit 10.9 to the Company's Annual Report on Form 10-K for the
              fiscal year ended December 31, 1995.)

       10.9   Agreement to purchase real estate dated December 18, 1995 between
              SBC Properties, L.L.C. (as agent for the Summit National Bank) and
              SunTrust Bank, Atlanta (incorporated by reference to Exhibit 10.10
              to the Company's Annual Report on Form 10-K for the fiscal year
              ended December 31, 1995.)

       10.10  Agreement to purchase real estate dated June 20, 1996 between The
              Summit National Bank and Nationsbank, NA. (incorporated by
              reference to Exhibit 10.11 to the Company's Annual Report on Form
              10-K for the fiscal year ended December 31, 1996.)

       11.1   Statement Regarding Computation of Per Share Earnings.

       27.1   Financial Data Schedule (for SEC use only)

       27.2   Restated Financial Data Schedule (for SEC use only)
</TABLE>

       b)     Reports on Form 8-K

       On April 7, 1998, the Company filed a Current Report on Form 8-K to
       report execution of the agreement to acquire California Security Bank.
       The item reported was "Item 5 - Other Events".

       On July 14, 1998, the Company filed a Current Report on Form 8-K to
       report consummation of its acquisition of California Security Bank. The
       items reported were "Item 2 - Acquisition or Disposition of Assets" and
       "Item 7 - Financial Statements, Pro-Forma Financial Information and
       Exhibits" (to be filed by amendment).




                                 Page 13 of 19


<PAGE>   14





                                   SIGNATURES


Pursuant to the requirements of the Securities Exchange Act of 1934, the
Registrant has duly caused this Report to be signed by the undersigned,
thereunto duly authorized.



                              SUMMIT BANK CORPORATION                     
                                                                          
                              BY:   /s/ David Yu                          
                                    ------------------------------------- 
                                    David Yu                              
                                    President and Chief Executive Officer 
                                                                          
                                                                          
                                                                          
                              BY:   /s/ Gary K. McClung                   
                                    ------------------------------------- 
                                    Gary K. McClung                       
                                    Executive Vice President              
                                    (Principal Financial Officer          
                                    and Principal Accounting Officer)     
                                                                          
                              DATE:       August 13, 1998                 
                                     ------------------------------------ 
                              











                                 Page 14 of 19


<PAGE>   15




                               INDEX TO EXHIBITS
<TABLE>
<CAPTION>
     Exhibit                                                               Page
     -------                                                               ----

     <S>   <C>                                                 
      2.1  Agreement and plan of merger by and between the
           Summit National Bank and California Security Bank,
           dated March 27, 1998 (incorporated by reference to
           Exhibit 2.1 to the Company's current report on Form 8-K
           dated April7, 1998.)

      3.1  Amended and Restated Articles of Incorporation
           of Summit Bank Corporation (incorporated by reference
           to Exhibit 3.2 of Summit Bank Corporation's
           Registration Statement on Form S-1, Amendment No.3
           (Registration Number 33-16366.)

      3.2  Bylaws of Summit Bank Corporation, as amended
           (incorporated by reference to Exhibit 3.2 to the
           Company's Annual Report on Form 10-K for the fiscal
           year ended December 31, 1987.)

      4.1  The rights of security holders are defined in
           (i) Articles Five, Six, Nine, Ten, Eleven, Thirteen,
           Fourteen, and Sixteen of the Amended and Restated
           Articles of Incorporation of Summit Bank Corporation
           and (ii) Articles Two, Three, Eight, Ten, and Eleven of
           the amended Bylaws of Summit Bank Corporation,
           (incorporated by reference to Exhibits 3.1 and 3.2
           respectively, to the Company's Annual Report on Form
           10-K for the year ended December 31, 1994.)

      10.1 Summit Bank Corporation 1987 Key Employee
           Incentive Stock Option Plan, as amended and restated as
           of February 28, 1989 (incorporated by reference to
           Exhibit 10.1 to the Company's Annual Report on Form
           10-K for the fiscal year ended December 31, 1991.)

      10.2 Form of Summit Bank Corporation Organizer's
           Warrant Agreement (incorporated by reference to Exhibit
           10.4 of Summit Bank Corporation's Registration
           Statement on Form S-1 (Registration Number 33-16366.)

      10.3 Lease Agreement dated December 3, 1993, between
           Baker Dennard Co., Lessor, and Summit National Bank,
           Lessee (incorporated by reference to Exhibit 10.4 to
           the Company's Annual Report on Form 10-K for the fiscal
           year ended December 31, 1993.)

      10.4 Lease agreement dated June 16, 1995, between
           ZML-Paces Limited Partnership, Lessor and Summit
           National Bank, Lessee (incorporated by reference to
           Exhibit 10.6 to the Company's Annual Report on Form
           10-K for the fiscal year ended December 31, 1995.)

      10.5 Change in Control Agreement dated August 25,
           1995 by and between Pin Pin Chau, President of the
           Summit National Bank, and the Summit National Bank
           (incorporated by reference to Exhibit 10.7 to the
           Company's Annual Report on Form 10-K for the fiscal
           year ended December 31, 1995.)

      10.6 Change in Control Agreement dated August 25,
           1995 by and between David Yu, Chairman of the Summit
           National Bank, and the Summit National Bank
           (incorporated by reference to Exhibit 10.8 to the
           Company's Annual Report on Form 10-K for the fiscal
           year ended December 31, 1995.)

      10.7 Change in Control Agreement dated August 25,
           1995 by and between Alec Dudley, Executive Vice
           President of the Summit National Bank, and the Summit
           National Bank (incorporated by reference to Exhibit
           10.9 to the Company's Annual Report on Form 10-K for
           the fiscal year ended December 31, 1995.)
</TABLE>


                                 Page 15 of 19


<PAGE>   16

<TABLE>
      <S>    <C>                                                             <C>
      10.8   Change in Control Agreement dated August 25,
             1995 by and between Gary K. McClung, Executive Vice
             President of the Summit National Bank, and the Summit
             National Bank (incorporated by reference to Exhibit
             10.9 to the Company's Annual Report on Form 10-K for
             the fiscal year ended December 31, 1995.)

      10.9   Agreement to purchase real estate dated December
             18, 1995 between SBC Properties, L.L.C. (as agent for
             the Summit National Bank) and SunTrust Bank, Atlanta
             (incorporated by reference to Exhibit 10.10 to the
             Company's Annual Report on Form 10-K for the fiscal
             year ended December 31, 1995.)

      10.10  Agreement to purchase real estate dated June
             20, 1996 between The Summit National Bank and
             Nationsbank, NA. (incorporated by reference to Exhibit
             10.11 to the Company's Annula Report on Form 10-K for
             the fiscal year ended December 31, 1996.)

     11.1    Statement Regarding Computation of Per Share Earnings.          17

     27.1    Financial Data Schedule (for SEC use only)                      18

     27.2    Restated Financial Data Schedule (for SEC use only)             19
</TABLE>


























                                 Page 16 of 19