<PAGE>
 
                      SECURITIES AND EXCHANGE COMMISSION
                            Washington, D.C. 20549



                                   FORM 10-Q



Quarterly Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act
                                    of 1934


                 For the Quarterly Period Ended    March 31, 1998
                                                   --------------


                          Commission File No. 1-10982
                                              -------



                          CROSS TIMBERS ROYALTY TRUST



        Texas                                        I.R.S. No. 75-6415930



                               NationsBank, N.A.
                                 P.O. Box 1317
                         Fort Worth, Texas 76101-1317

                         Telephone Number 817/390-6592



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 and (2) has been subject to such filing requirements for
the past 90 days.  Yes  X   No
                       ---     ---    

Number of units of beneficial interest outstanding at May 1, 1998:  6,000,000
                                                                    ---------
<PAGE>
 
CROSS TIMBERS ROYALTY TRUST

PART I - FINANCIAL STATEMENTS
-----------------------------



Item 1.  Financial Statements.

The condensed financial statements included herein are presented, without audit,
pursuant to the rules and regulations of the Securities and Exchange Commission.
Certain information and footnote disclosures normally included in annual
financial statements have been condensed or omitted pursuant to such rules and
regulations, although the Trustee believes that the disclosures are adequate to
make the information presented not misleading.  These condensed financial
statements should be read in conjunction with the financial statements and the
notes thereto included in the Trust's latest annual report on Form 10-K.  In the
opinion of the Trustee, all adjustments, consisting only of normal recurring
adjustments, necessary to present fairly the assets, liabilities and trust
corpus of the Cross Timbers Royalty Trust at March 31, 1998, and the
distributable income and changes in trust corpus for the three-month periods
ended March 31, 1998 and 1997, have been included.  Distributable income for
such interim periods is not necessarily indicative of the distributable income
for the full year.

                                                                               2
<PAGE>
 
REPORT OF INDEPENDENT PUBLIC ACCOUNTANTS



NationsBank, N.A., as Trustee
 for the Cross Timbers Royalty Trust:

We have reviewed the accompanying condensed statement of assets, liabilities and
trust corpus of the Cross Timbers Royalty Trust as of March 31, 1998 and the
related condensed statements of distributable income and changes in trust corpus
for the three-month periods ended March 31, 1998 and 1997.  These financial
statements are the responsibility of the Trustee.

We conducted our review in accordance with standards established by the American
Institute of Certified Public Accountants.  A review of interim financial
information consists principally of applying analytical procedures to financial
data and making inquiries of persons responsible for financial and accounting
matters. It is substantially less in scope than an audit in accordance with
generally accepted auditing standards, the objective of which is the expression
of an opinion regarding the financial statements taken as a whole. Accordingly,
we do not express such an opinion.

The accompanying condensed financial statements are prepared on a modified cash
basis as described in Note 1 which is a comprehensive basis of accounting other
than generally accepted accounting principles.

Based on our review, we are not aware of any material modifications that should
be made to such condensed financial statements for them to be in conformity with
the basis of accounting described in Note 1.

We have previously audited, in accordance with generally accepted auditing
standards, the statement of assets, liabilities and trust corpus of the Cross
Timbers Royalty Trust as of December 31, 1997 included in the Trust's 1997
annual report on Form 10-K, and in our report dated March 18, 1998, we expressed
an unqualified opinion on that statement.  In our opinion, the information set
forth in the accompanying condensed statement of assets, liabilities and trust
corpus as of December 31, 1997 is fairly stated in all material respects in
relation to the statement of assets, liabilities and trust corpus included in
the Trust's 1997 annual report on Form 10-K from which it has been derived.



ARTHUR ANDERSEN LLP

Fort Worth, Texas
May 7, 1998

                                                                               3
<PAGE>
 
CROSS TIMBERS ROYALTY TRUST
------------------------------------------------------------------------------- 

CONDENSED STATEMENTS OF ASSETS, LIABILITIES AND TRUST CORPUS

<TABLE>
<CAPTION>
 
 
                                                     MARCH 31,      DECEMBER 31,
                                                       1998             1997  
                                                   -----------     -------------
                                                   (Unaudited)      
<S>                                               <C>              <C>
                                                               
ASSETS                                                         
                                                               
Cash and short-term investments..................  $   536,526      $    662,486
                                                               
Interest to be received..........................          885             1,065
                                                               
Net overriding royalty interests in oil and gas                
  properties - net (Note 1)......................   37,423,696        38,104,367
                                                   -----------      ------------
                                                               
                                                   $37,961,107      $ 38,767,918
                                                   ===========      ============
                                                               
                                                               
LIABILITIES AND TRUST CORPUS                                   
                                                               
Distribution payable to Unit holders.............  $   537,411      $    663,551
                                                               
Trust corpus (6,000,000 Units of beneficial                    
  interest authorized and outstanding)...........   37,423,696        38,104,367
                                                   -----------      ------------
                                                               
                                                   $37,961,107      $ 38,767,918
                                                   ===========      ============
 
</TABLE>



The accompanying notes to condensed financial statements are an integral part of
these statements.

                                                                               4
<PAGE>
 
CROSS TIMBERS ROYALTY TRUST
------------------------------------------------------------------------------- 

CONDENSED STATEMENTS OF DISTRIBUTABLE INCOME (Unaudited)

<TABLE>
<CAPTION>
 
 
                                                  THREE MONTHS ENDED MARCH 31,
                                                  ----------------------------
                                                      1998           1997
                                                  -------------  -------------
<S>                                               <C>            <C>
 
Royalty income..................................    $2,335,418     $3,114,590

Interest income.................................         3,771          4,350
                                                    ----------     ----------
                                        
Total income....................................     2,339,189      3,118,940
                                        
Administration expense..........................        44,220         49,405
                                                    ----------     ----------
                                        
Distributable income............................    $2,294,969     $3,069,535
                                                    ==========     ==========

Distributable income per Unit (6,000,000 Units)     $ 0.382494     $ 0.511589
                                                    ==========     ========== 
</TABLE> 




The accompanying notes to condensed financial statements are an integral part of
these statements.

                                                                               5
<PAGE>
 
CROSS TIMBERS ROYALTY TRUST
--------------------------------------------------------------------------------

CONDENSED STATEMENTS OF CHANGES IN TRUST CORPUS (Unaudited)

<TABLE>
<CAPTION>
 
 
                                                     THREE MONTHS ENDED MARCH 31,
                                                    ------------------------------
                                                         1998            1997
                                                    --------------  --------------
<S>                                                 <C>             <C>
 
Trust Corpus, beginning of period.................    $38,104,367     $41,337,673
 
Amortization of net overriding royalty interests..       (680,671)       (849,382)
 
Distributable income..............................      2,294,969       3,069,535
 
Distributions declared............................     (2,294,969)     (3,069,535)
                                                      -----------     -----------
 
Trust Corpus, end of period.......................    $37,423,696     $40,488,291
                                                      ===========     ===========
 
</TABLE>



The accompanying notes to condensed financial statements are an integral part of
these statements.

                                                                               6
<PAGE>
 
CROSS TIMBERS ROYALTY TRUST
--------------------------------------------------------------------------------
NOTES TO CONDENSED FINANCIAL STATEMENTS (Unaudited)



1.  BASIS OF ACCOUNTING

    The financial statements of Cross Timbers Royalty Trust ("the Trust") are
    prepared on the following basis:

    -  Royalty income recorded for a month is the amount computed and paid by
       the interest owner, Cross Timbers Oil Company ("Cross Timbers Oil"), to
       NationsBank, N.A. ("Trustee"), as Trustee for the Trust. Royalty income
       consists of the amounts received by Cross Timbers Oil from the sale of
       production less applicable costs ("net proceeds") from the properties
       underlying the net overriding royalty interests ("Royalty Trust
       Interests") conveyed to the Trust. Net proceeds are multiplied by net
       profit percentages of 90% in the case of Royalty Trust Interests carved
       from certain royalty interests in New Mexico, Oklahoma and Texas ("90%
       Royalty Trust Interests") and 75% in the case of Royalty Trust Interests
       carved from seven working interest properties in Oklahoma and Texas ("75%
       Royalty Trust Interests").

       Applicable costs deducted in the calculation of net proceeds for the 90%
       Royalty Trust Interests generally include applicable taxes,
       transportation, marketing and legal costs, and do not include other
       production and development costs. For the 75% Royalty Trust Interests,
       such costs include production expenses, development costs, applicable
       taxes, operating charges and other costs.

    -  Royalty income is computed separately for each of five conveyances under
       which the Royalty Trust Interests were conveyed to the Trust. If monthly
       costs exceed revenues for any conveyance ("excess costs"), such excess
       cannot reduce royalty income from other conveyances, but is carried
       forward with accrued interest to be recovered from future net proceeds of
       that conveyance. See Note 3.

    -  Interest income, interest to be received and distribution payable to Unit
       holders include interest to be earned from the monthly record date (last
       business date of the month) through the date of the next distribution to
       Unit holders.

    -  Trust expenses are recorded based on liabilities paid and cash reserves
       established by the Trustee for liabilities and contingencies.

    -  Distributions to Unit holders are recorded when declared by the Trustee.

    The financial statements of the Trust differ from financial statements
    prepared in accordance with generally accepted accounting principles
    ("GAAP") because revenues are not accrued in the month of production,
    expenses are recognized when paid rather than when incurred, and certain
    cash reserves may be established for contingencies which would not be
    accrued under GAAP. The initial carrying value of the Royalty Trust
    Interests ($61,100,449) represents the net book value from the historical
    accounting records (successful efforts method) of predecessors to Cross
    Timbers Oil on February 12, 1991. Amortization of the Royalty Trust
    Interests is calculated on a unit-of-production basis and is charged
    directly to trust corpus. Accumulated amortization as of March 31, 1998 and
    December 31, 1997 is $23,676,753 and $22,996,082, respectively.

                                                                               7
<PAGE>
 
2.  FEDERAL INCOME TAXES

    Tax counsel has advised the Trust that, under current tax laws, the Trust
    will be classified as a grantor trust for Federal income tax purposes and
    therefore is not subject to taxation at the trust level. However, the
    opinion of tax counsel is not binding on the Internal Revenue Service.

    The Unit holders are considered, for Federal income tax purposes, to own the
    Trust's income and principal as though no trust were in existence. The
    income of the Trust is deemed to have been received or accrued by the Unit
    holders at the time such income is received or accrued by the Trust, rather
    than when distributed by the Trust.

    Cross Timbers Oil has advised the Trustee that the Trust receives royalty
    income from coal seam gas wells. Production from coal seam gas wells drilled
    after December 31, 1979, and prior to January 1, 1993, qualifies for the
    Federal income tax credit for producing nonconventional fuels under Section
    29 of the Internal Revenue Code. This tax credit, which was approximately
    $1.05 per MMBtu for 1997, is recalculated annually based on each year's
    qualifying production through the year 2002. Such credit, based on the Unit
    holder's pro rata share of qualifying production, may not reduce his regular
    tax liability (after the foreign tax credit and certain other non-refundable
    credits) below his tentative minimum tax. Any part of the Section 29 credit
    not allowed for the tax year solely because of this limitation is subject to
    certain carryover provisions. Unit holders should consult their tax advisors
    regarding Trust tax compliance matters.

    Based on 1998 qualifying sales volumes and the factors used in the
    calculation of the 1997 coal seam tax credit, the credit for the quarter
    ended March 31, 1998 is estimated to be $.037 per Unit. The actual coal seam
    credit for the quarter ended March 31, 1997 was $.052 per Unit. The decline
    in the first quarter coal seam tax credit from 1997 to 1998 is primarily
    because of adjustments to prior period coal seam gas sales volumes. Final
    1998 coal seam tax credit data will be provided to Unit holders with year-
    end tax information.


3.  EXCESS COSTS

    Cross Timbers Oil has advised the Trustee that, in the calculation of
    royalty income for the month of April 1998, costs exceeded revenues for the
    Texas conveyance of the 75% Royalty Trust Interests by $92,914. Such excess
    costs plus accrued interest must be recovered from future net proceeds of
    the Texas conveyance of the 75% Royalty Trust Interests before this
    conveyance can again contribute to Trust royalty income. See Item 2,
    "Trustee's Discussion and Analysis - Excess Costs."

 

                                                                               8
<PAGE>
 
Item 2.  Trustee's Discussion and Analysis.

Three Months Ended March 31, 1998 and 1997
------------------------------------------

For the quarter ended March 31, 1998, royalty income was $2,335,418, compared
with $3,114,590 for the first quarter of 1997.  This 25% decrease in royalty
income is primarily the result of significantly lower oil prices and decreased
gas sales volumes.

After considering interest income of $3,771 and administration expense of
$44,220, distributable income for first quarter 1998 was $2,294,969, or
$0.382494 per Unit of beneficial interest.  Distributions of $0.148984,
$0.143942 and $0.089568 per Unit were made to Unit holders of record on January
30, February 27 and March 31, 1998, respectively.  Distributable income for
first quarter 1997 was $3,069,535, or $0.511589 per Unit.

Royalty income is recorded when received by the Trust, which is the month
following receipt by Cross Timbers Oil, and generally two months after oil
production and three months after gas production.  Royalty income is generally
affected by three major factors:  1) oil and gas sales volumes, 2) oil and gas
sales prices and 3) costs deducted in the calculation of royalty income.
Because properties underlying the 90% Royalty Trust Interests are royalty and
overriding royalty interests, they generally bear no costs other than production
and property taxes, related legal costs, and marketing and transportation
charges.  In addition to these costs, the 75% Royalty Trust Interests are
subject to production and development costs, since the properties underlying the
75% Royalty Trust Interests are working interests.

Volumes

Oil sales volumes decreased 1% from first quarter 1997 to 1998 because of
natural production decline, partially offset by the timing of cash receipts. Gas
sales volumes decreased 12% from first quarter 1997 to 1998, primarily because
of volume adjustments related to prior periods and the timing of cash receipts.
Excluding such prior period adjustments and cash receipt timing differences, gas
sales volumes declined approximately 2% from first quarter 1997 to 1998. Such 2%
decline includes an estimated 4% natural decline in gas production, partially
offset by a 2% increase in gas sales volumes related to new wells drilled during
1997 on some of the Texas 90% Royalty Trust Interests.

Prices

The average oil price for first quarter 1998 was $16.15 per barrel, a decrease
of 29% from the first quarter 1997 average price of $22.62.    Because of the
two-month interval between oil production and receipt by the Trust of related
royalty income, the first quarter 1997 average price reflects the rise in oil
prices to six-year highs in December 1996 and January 1997.  Similarly, the
first quarter 1998 average oil price includes two months of lower prices
following the sharp decline in oil prices that began in December 1997.  After
hitting a decade-low of $11.00, prices began to increase in late March.  The
average posted West Texas Intermediate oil price for February through April 1998
(related to royalty income to be received by the Trust in second quarter 1998)
was $13.26.

The first quarter 1998 average gas price was $2.59 per thousand cubic feet
("Mcf"), or 2% above the first quarter 1997 price of $2.53.  Cross Timbers Oil
has advised the Trustee that it expects the average gas price for first quarter
1998 production (related to royalty income to be received by the Trust in second
quarter 1998) to decline to approximately $1.90 because of reduced demand during
a milder than normal winter.

                                                                               9
<PAGE>
 
Costs

Costs deducted in the calculation of first quarter 1998 royalty income (see
"Calculation of Royalty Income") increased 5% or $61,876 from total costs for
first quarter 1997.  This was a result of a 14% or $87,362 increase in
production expenses, partially offset by an 8% or $12,840 decrease in
development costs and a 4% or $12,646 decrease in production and property taxes.
Changes in production expense and development costs are primarily related to the
timing of maintenance and development projects on the underlying working
interest properties.  Decreased Oklahoma drilling costs offset costs related to
a carbon dioxide injection project that began on one of the Texas underlying
working interest properties in 1998.  See "Excess Costs" below.  Production
taxes decreased with decreased oil and gas revenues, partially offset by
increased estimated property taxes.

Excess Costs

Cross Timbers Oil has advised the Trustee that, in the calculation of Trust
royalty income for the month of April 1998, costs exceeded revenues by $92,914
for the Texas conveyance of the 75% Royalty Trust Interests. Such excess costs
are the result of lower oil prices and increased development costs related to
the carbon dioxide injection project that began during the first quarter.
Excess costs from one conveyance cannot reduce royalty income computed under
another conveyance; therefore, cumulative excess costs plus accrued interest
must be recovered from future net proceeds of the underlying Texas working
interest properties before these properties can again contribute to Trust
royalty income.  The Texas 75% Royalty Trust Interests contributed approximately
$0.07 per Unit to first quarter 1997 royalty income, or 14% of first quarter
1997 distributions. Primarily because of lower oil prices in December 1997 and
January 1998, the Texas 75% Royalty Trust Interests contributed only $0.015 per
Unit to first quarter 1998 royalty income, or 4% of first quarter 1998
distributions.

Amortization

Amortization of Royalty Trust Interests, which is directly charged to trust
corpus, decreased to $680,671 for first quarter 1998 from $849,382 for the prior
year quarter.  Decreased amortization is the result of lower gas sales volumes
for the quarter, as well as reduced oil sales volumes allocated to the Royalty
Trust Interests because of lower oil prices.

                                                                              10
<PAGE>
 
COMPARATIVE OIL AND GAS SALES

Oil and gas sales attributable to the Underlying Properties and the Royalty
Trust Interests are as follows:
<TABLE>
<CAPTION>
 
                                    Three Months Ended March 31, (a)
                                    --------------------------------
                                         1998             1997
                                    ---------------  ---------------
<S>                                 <C>              <C>
  OIL SALES (Bbls)................
 
     Underlying Properties (b)....          104,686          105,459
       Average per day............            1,138            1,146
       Average price..............           $16.15           $22.62
 
     Royalty Trust Interests (b)..           37,062           55,539
 
  GAS SALES (Mcf).................
 
     Underlying Properties (b)....          835,901          945,887
       Average per day............            9,086           10,281
       Average price..............            $2.59            $2.53
 
     Royalty Trust Interests (b)..          725,665          835,124
</TABLE>
(a) Because of the interval between time of production and receipt of royalty
    income by the Trust, oil and gas sales for the quarter ended March 31
    generally represent oil production for the period November through January
    and gas production for the period October through December.

(b) Oil and gas sales volumes are allocated to the Royalty Trust Interests based
    upon a formula that considers oil and gas prices and the total amount of
    production expenses and development costs.  Changes in any of these factors
    may result in disproportionate fluctuations in volumes allocated to the
    Royalty Trust Interests.  Therefore, comparative discussion of oil and gas
    sales is based on the Underlying Properties.

                                                                              11
<PAGE>
 
CALCULATION OF ROYALTY INCOME

The following is the calculation of royalty income received by the Trust for the
quarters ended March 31, 1998 and 1997.  See Note 1 to Condensed Financial
Statements.
<TABLE>
<CAPTION>
 
                                      Three Months Ended March 31,   
                             -------------------------------------------------
                                     1998                       1997
                             -----------------------   -----------------------
                                 90%          75%          90%          75%
                               Royalty      Royalty      Royalty      Royalty
                                Trust        Trust        Trust        Trust
                              Interests    Interests    Interests    Interests
                             ----------   ----------   ----------   ----------
<S>                          <C>          <C>          <C>          <C> 
REVENUES...................  
 Oil sales.................  $  410,780   $1,279,730   $  490,486   $1,894,773
 Gas sales.................   2,115,125       45,704    2,317,868       74,712
                             ----------   ----------   ----------   ----------
 
  Total....................   2,525,905    1,325,434    2,808,354    1,969,485
                             ----------   ----------   ----------   ----------
 
COSTS......................
 Production and property
  taxes....................     211,444      136,366      232,135      128,321
 Production expenses (a)                     705,541        9,162      609,017
 Development costs.........         -        146,989         -         159,829
                             ----------   ----------   ----------   ----------
 
 
  Total....................     211,444      988,896      241,297      897,167
                             ----------   ----------   ----------   ----------
 
Net Proceeds...............   2,314,461      336,538    2,567,057    1,072,318
 
Net Profits Percentage.....          90%          75%          90%          75%
                             ----------   ----------   ----------   ----------
 
ROYALTY INCOME.............  $2,083,015   $  252,403   $2,310,351   $  804,239
                             ==========   ==========   ==========   ==========
 
</TABLE>
(a) Production expenses for the 75% Royalty Trust Interests include an overhead
    fee that is deducted and retained by Cross Timbers Oil.  This fee is
    currently $19,438 per month, or $58,314 per quarter.  This overhead fee is
    subject to adjustment each May based on an oil and gas industry index.

                                                                              12
<PAGE>
 
PART II - OTHER INFORMATION
---------------------------


Items 1 through 4.    Not applicable.

Item 5.     Other Information.

            At the close of business on May 6, 1998, the Trustee merged with and
            into NationsBank, N.A. The Trustee is now NationsBank, N.A.,
            successor by merger to NationsBank of Texas, N.A., as Trustee.

Item 6. (a) Exhibits.
                                                                            Page
                                                                            ----

  (4)   (a) Cross Timbers Royalty Trust Indenture Amended and Restated on
            January 13, 1992 by NationsBank of Texas, N.A.(now NationsBank,
            N.A.), as Trustee, heretofore filed as Exhibit 3.1 to the Trust's
            Registration Statement No. 33-44385 filed with the Securities and
            Exchange Commission on February 19, 1992, is incorporated herein by
            reference.

        (b) Net Overriding Royalty Conveyance (Cross Timbers Royalty Trust, 
            90% - Texas) from South Timbers Limited Partnership, West 
            Timbers Limited Partnership, North Timbers Limited Partnership, 
            East Timbers Limited Partnership, Hickory Timbers Limited 
            Partnership, and Cross Timbers Partners, L.P. (predecessors 
            of Cross Timbers Oil Company, L.P. which subsequently merged 
            into Cross Timbers Oil Company) to NCNB Texas National Bank (now
            NationsBank, N.A.), as Trustee, dated February 12, 1991 (without
            Schedules A and B), heretofore filed as Exhibit 10.1 to the Trust's
            Registration Statement No. 33-44385 filed with the Securities and
            Exchange Commission on February 19, 1992, is incorporated herein by
            reference.

        (c) Net Overriding Royalty Conveyance (Cross Timbers Royalty Trust, 
            75% - Texas) from South Timbers Limited Partnership, West Timbers 
            Limited Partnership, North Timbers Limited Partnership, East Timbers
            Limited Partnership, Hickory Timbers Limited Partnership, and Cross
            Timbers Partners, L.P. (predecessors of Cross Timbers Oil Company,
            L.P. which subsequently merged into Cross Timbers Oil Company) to
            NCNB Texas National Bank (now NationsBank, N.A.), as Trustee, dated
            February 12, 1991 (without Schedules A and B), heretofore filed as
            Exhibit 10.5 to the Trust's Registration Statement No. 33-44385
            filed with the Securities and Exchange Commission on February 19,
            1992, is incorporated herein by reference.

  (15)  (a) Awareness letter of Arthur Andersen LLP                          15


        (b) Reports on Form 8-K.

            No reports on Form 8-K have been filed during the quarter for which
this report is filed.

                                                                              13
<PAGE>
 
                                  SIGNATURES


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


                                  CROSS TIMBERS ROYALTY TRUST
                                  By NATIONSBANK, N.A., TRUSTEE
 


                                  By    JOE B. GRISSOM
                                     -----------------------------
                                        Joe  B. Grissom
                                        Vice President



                                  CROSS TIMBERS OIL COMPANY



Date: May 13, 1998                By    LOUIS G. BALDWIN
                                     -----------------------------
                                        Louis G. Baldwin
                                     Senior Vice President and
                                      Chief Financial Officer

                                                                              14