<PAGE>   1

                       SECURITIES AND EXCHANGE COMMISSION

                             WASHINGTON, D.C. 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, 1999

                                       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 0-18982

                             IEA INCOME FUND X, L.P.
             (Exact name of registrant as specified in its charter)


            California                                        94-3098648
 -------------------------------                           ------------------
 (State or other jurisdiction of                            (I.R.S. Employer
  incorporation or organization)                           Identification No.)

         444 Market Street, 15th Floor, San Francisco, California 94111
         (Address of principal executive offices)             (Zip Code)

                                 (415) 677-8990
              (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 [ ].



<PAGE>   2

                             IEA INCOME FUND X, L.P.

                  REPORT ON FORM 10-Q FOR THE QUARTERLY PERIOD
                               ENDED JUNE 30, 1999

                                TABLE OF CONTENTS



<TABLE>
<CAPTION>
                                                                                                PAGE
<S>                                                                                             <C>
PART I - FINANCIAL INFORMATION

 Item 1. Financial Statements
         Balance Sheets - June 30, 1999 (unaudited) and December 31, 1998                         4
         Statements of Operations for the three and six months ended June 30,
         1999 and 1998 (unaudited)                                                                5
         Statements of Cash Flows for the six months ended June 30, 1999
           and 1998 (unaudited)                                                                   6
         Notes to Financial Statements (unaudited)                                                7
 Item 2. Management's Discussion and Analysis of Financial Condition and Results of Operations   10
 Item 3. Quantitative and Qualitative Disclosures About Market Risk                              12

PART II- OTHER INFORMATION
 Item 1. Legal Proceedings                                                                       13
 Item 3. Defaults Upon Senior Securities                                                         13
 Item 5. Other Information                                                                       13
 Item 6. Exhibits and Reports on Form 8-K                                                        14
</TABLE>



                                       2
<PAGE>   3

                         PART I - FINANCIAL INFORMATION


Item 1. Financial Statements

        Presented herein are the Registrant's balance sheets as of June 30, 1999
        and December 31, 1998, statements of operations for the three and six
        months ended June 30, 1999 and 1998, and statements of cash flows for
        the six months ended June 30, 1999 and 1998.



                                       3
<PAGE>   4


                             IEA INCOME FUND X, L.P.

                                 BALANCE SHEETS

                                   (UNAUDITED)



<TABLE>
<CAPTION>
                                                                              June 30,           December 31,
                                                                                1999                 1998
                                                                            ------------         ------------
<S>                                                                         <C>                  <C>
                 Assets

Current assets:
   Cash and cash equivalents, includes $566,819 at June 30, 1999 and
      $653,751 at December 31, 1998 in interest-bearing accounts            $    566,919         $    653,851
   Net lease receivables due from Leasing Company
      (notes 1 and 2)                                                            130,100              199,488
                                                                            ------------         ------------

         Total current assets                                                    697,019              853,339
                                                                            ------------         ------------

Container rental equipment, at cost                                           15,818,357           16,545,596
   Less accumulated depreciation                                               8,149,039            8,048,301
                                                                            ------------         ------------
      Net container rental equipment                                           7,669,318            8,497,295
                                                                            ------------         ------------

                                                                            $  8,366,337         $  9,350,634
                                                                            ============         ============
            Partners' Capital

Partners' capital (deficit):
   General partner                                                          $    (37,336)        $    (27,494)
   Limited partners                                                            8,403,673            9,378,128
                                                                            ------------         ------------

         Total partners' capital                                               8,366,337            9,350,634
                                                                            ------------         ------------

                                                                            $  8,366,337         $  9,350,634
                                                                            ============         ============
</TABLE>



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



                                       4
<PAGE>   5

                             IEA INCOME FUND X, L.P.

                            STATEMENTS OF OPERATIONS

                                   (UNAUDITED)



<TABLE>
<CAPTION>
                                                            Three Months Ended                  Six Months Ended
                                                        ---------------------------         ---------------------------
                                                         June 30,         June 30,          June 30,          June 30,
                                                           1999             1998              1999              1998
                                                        ---------         ---------         ---------         ---------
<S>                                                     <C>               <C>               <C>               <C>
Net lease revenue (notes 1 and 3)                       $ 227,987         $ 356,568         $ 503,588         $ 689,448

Other operating expenses:
   Depreciation                                           233,687           247,814           471,442           498,051
   Other general and administrative expenses                8,269             9,766            22,845            22,753
                                                        ---------         ---------         ---------         ---------
                                                          241,956           257,580           494,287           520,804
                                                        ---------         ---------         ---------         ---------

      Earnings (loss) from operations                     (13,969)           98,988             9,301           168,644

Other income (loss):
   Interest income                                          6,650             8,362            13,668            16,921
   Net loss on disposal of equipment                      (17,579)          (13,110)         (101,497)          (28,080)
                                                        ---------         ---------         ---------         ---------
                                                          (10,929)           (4,748)          (87,829)          (11,159)
                                                        ---------         ---------         ---------         ---------

      Net earnings (loss)                               $ (24,898)        $  94,240         $ (78,528)        $ 157,485
                                                        =========         =========         =========         =========

Allocation of net earnings (loss):
   General partner                                      $  14,021         $  14,897         $  26,040         $  29,483
   Limited partners                                       (38,919)           79,343          (104,568)          128,002
                                                        ---------         ---------         ---------         ---------

                                                        $ (24,898)        $  94,240         $ (78,528)        $ 157,485
                                                        =========         =========         =========         =========

Limited partners' per unit share of net earnings        $   (1.00)        $    2.02         $   (2.67)        $    3.26
                                                        =========         =========         =========         =========
</TABLE>



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



                                       5
<PAGE>   6

                             IEA INCOME FUND X, L.P.

                            STATEMENTS OF CASH FLOWS

                                   (UNAUDITED)



<TABLE>
<CAPTION>
                                                                 Six Months Ended
                                                           ---------------------------
                                                            June 30,          June 30,
                                                              1999             1998
                                                           ---------         ---------
<S>                                                        <C>               <C>
Net cash provided by operating activities                  $ 558,357         $ 603,160

Cash flows provided by investing activities:
   Proceeds from sale of container rental equipment          260,481           175,014

Cash flows used in financing activities:
   Distribution to partners                                 (905,770)         (820,234)
                                                           ---------         ---------


Net decrease in cash and cash equivalents                    (86,932)          (42,060)


Cash and cash equivalents at January 1                       653,851           714,528
                                                           ---------         ---------


Cash and cash equivalents at June 30                       $ 566,919         $ 672,468
                                                           =========         =========
</TABLE>



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



                                       6
<PAGE>   7

                             IEA INCOME FUND X, L.P.

                     NOTES TO UNAUDITED FINANCIAL STATEMENTS


(1) Summary of Significant Accounting Policies

    (a) Nature of Operations

        IEA Income Fund X, L.P. (the "Partnership") is a limited partnership
        organized under the laws of the State of California on July 18, 1989 for
        the purpose of owning and leasing marine cargo containers. Cronos
        Capital Corp. ("CCC") is the general partner and, with its affiliate
        Cronos Containers Limited (the "Leasing Company"), manages the business
        of the Partnership. The Partnership shall continue until December 31,
        2010, unless sooner terminated upon the occurrence of certain events.

        The Partnership commenced operations on January 17, 1990, when the
        minimum subscription proceeds of $1,000,000 were obtained. The
        Partnership offered 40,000 units of limited partnership interest at $500
        per unit, or $20,000,000. The offering terminated on October 30, 1990,
        at which time 39,206 limited partnership units had been purchased.

        As of June 30, 1999, the Partnership owned and operated 3,682
        twenty-foot, 1,018 forty-foot and 86 forty-foot high-cube marine dry
        cargo containers.

    (b) Leasing Company and Leasing Agent Agreement

        Pursuant to the Limited Partnership Agreement of the Partnership, all
        authority to administer the business of the Partnership is vested in
        CCC. CCC has entered into a Leasing Agent Agreement whereby the Leasing
        Company has the responsibility to manage the leasing operations of all
        equipment owned by the Partnership. Pursuant to the Agreement, the
        Leasing Company is responsible for leasing, managing and re-leasing the
        Partnership's containers to ocean carriers and has full discretion over
        which ocean carriers and suppliers of goods and services it may deal
        with. The Leasing Agent Agreement permits the Leasing Company to use the
        containers owned by the Partnership, together with other containers
        owned or managed by the Leasing Company and its affiliates, as part of a
        single fleet operated without regard to ownership. Since the Leasing
        Agent Agreement meets the definition of an operating lease in Statement
        of Financial Accounting Standards (SFAS) No. 13, it is accounted for as
        a lease under which the Partnership is lessor and the Leasing Company is
        lessee.

        The Leasing Agent Agreement generally provides that the Leasing Company
        will make payments to the Partnership based upon rentals collected from
        ocean carriers after deducting direct operating expenses and management
        fees to CCC. The Leasing Company leases containers to ocean carriers,
        generally under operating leases which are either master leases or term
        leases (mostly two to five years). Master leases do not specify the
        exact number of containers to be leased or the term that each container
        will remain on hire but allow the ocean carrier to pick up and drop off
        containers at various locations; rentals are based upon the number of
        containers used and the applicable per-diem rate. Accordingly, rentals
        under master leases are all variable and contingent upon the number of
        containers used. Most containers are leased to ocean carriers under
        master leases; leasing agreements with fixed payment terms are not
        material to the financial statements. Since there are no material
        minimum lease rentals, no disclosure of minimum lease rentals is
        provided in these financial statements.

                                                                     (Continued)



                                       7
<PAGE>   8

                             IEA INCOME FUND X, L.P.

                     NOTES TO UNAUDITED FINANCIAL STATEMENTS


    (c) Basis of Accounting

        The Partnership utilizes the accrual method of accounting. Net lease
        revenue is recorded by the Partnership in each period based upon its
        leasing agent agreement with the Leasing Company. Net lease revenue is
        generally dependent upon operating lease rentals from operating lease
        agreements between the Leasing Company and its various lessees, less
        direct operating expenses and management fees due in respect of the
        containers specified in each operating lease agreement.

    (d) Financial Statement Presentation

        These financial statements have been prepared without audit. Certain
        information and footnote disclosures normally included in financial
        statements prepared in accordance with generally accepted accounting
        procedures have been omitted. It is suggested that these financial
        statements be read in conjunction with the financial statements and
        accompanying notes in the Partnership's latest annual report on Form
        10-K.

        The preparation of financial statements in conformity with generally
        accepted accounting principles (GAAP) requires the Partnership to make
        estimates and assumptions that affect the reported amounts of assets and
        liabilities and disclosure of contingent assets and liabilities at the
        date of the financial statements and the reported amounts of revenues
        and expenses during the reported period. Actual results could differ
        from those estimates.

        The interim financial statements presented herewith reflect all
        adjustments of a normal recurring nature which are, in the opinion of
        management, necessary to a fair statement of the financial condition and
        results of operations for the interim periods presented.


(2) Net Lease Receivables Due from Leasing Company

        Net lease receivables due from the Leasing Company are determined by
        deducting direct operating payables and accrued expenses, base
        management fees payable, and reimbursed administrative expenses payable
        to CCC and its affiliates from the rental billings payable by the
        Leasing Company to the Partnership under operating leases to ocean
        carriers for the containers owned by the Partnership. Net lease
        receivables at June 30, 1999 and December 31, 1998 were as follows:


<TABLE>
<CAPTION>
                                                                    June 30,       December 31,
                                                                      1999            1998
                                                                    --------        --------
<S>                                                                 <C>            <C>
Lease receivables, net of doubtful accounts of
   $62,980 at June 30, 1999 and $61,113 at December 31, 1998        $468,652        $534,261

Less:
Direct operating payables and accrued expenses                       200,184         185,539
Damage protection reserve                                             84,967          86,231
Base management fees                                                  46,017          54,020
Reimbursed administrative expenses                                     7,384           8,983
                                                                    --------        --------

                                                                    $130,100        $199,488
                                                                    ========        ========
</TABLE>
                                                                     (Continued)


                                       8
<PAGE>   9

                             IEA INCOME FUND X, L.P.

                     NOTES TO UNAUDITED FINANCIAL STATEMENTS


(3) Net Lease Revenue

        Net lease revenue is determined by deducting direct operating expenses,
        base management fees and reimbursed administrative expenses to CCC from
        the rental revenue billed by the Leasing Company under operating leases
        to ocean carriers for the containers owned by the Partnership. Net lease
        revenue for the three and six-month periods ended June 30, 1999 and 1998
        was as follows:


<TABLE>
<CAPTION>
                                               Three Months Ended                  Six Months Ended
                                          ----------------------------        ----------------------------
                                           June 30,          June 30,          June 30,          June 30,
                                             1999              1998              1999              1998
                                          ----------        ----------        ----------        ----------
<S>                                       <C>               <C>               <C>               <C>
Rental revenue (note 4)                   $  422,429        $  551,406        $  885,169        $1,112,596
Less:
Rental equipment operating expenses          138,962           126,479           267,565           273,911
Base management fees                          28,784            37,692            60,955            76,658
Reimbursed administrative expenses            26,696            30,667            53,061            72,579
                                          ----------        ----------        ----------        ----------

                                          $  227,987        $  356,568        $  503,588        $  689,448
                                          ==========        ==========        ==========        ==========
</TABLE>

(4) Operating Segment

        The Financial Accounting Standards Board has issued SFAS No. 131,
        "Disclosures about Segments of an Enterprise and Related Information,"
        which changes the way public business enterprises report financial and
        descriptive information about reportable operating segments. An
        operating segment is a component of an enterprise that engages in
        business activities from which it may earn revenues and incur expenses,
        whose operating results are regularly reviewed by the enterprise's chief
        operating decision maker to make decisions about resources to be
        allocated to the segment and assess its performance, and about which
        separate financial information is available. Management operates the
        Partnership's container fleet as a homogenous unit and has determined,
        after considering the requirements of SFAS No. 131, that as such it has
        a single reportable operating segment.

        The Partnership derives its revenues from owning and leasing marine
        cargo containers. As of June 30, 1999, the Partnership operated 3,682
        twenty-foot, 1,018 forty-foot and 86 forty-foot high-cube marine dry
        cargo containers.

        Due to the Partnership's lack of information regarding the physical
        location of its fleet of containers when on lease in the global shipping
        trade, it is impracticable to provide the geographic area information
        required by SFAS No. 131. Any attempt to separate "foreign" operations
        from "domestic" operations would be dependent on definitions and
        assumptions that are so subjective as to render the information
        meaningless and potentially misleading.



                                       9
<PAGE>   10

Item 2. Management's Discussion and Analysis of Financial Condition and Results
of Operations

        It is suggested that the following discussion be read in conjunction
        with the Registrant's most recent annual report on Form 10-K.


1)      Material changes in financial condition between June 30, 1999 and
        December 31, 1998.

        During the first six months of 1999, the Registrant disposed of 215
        containers as part of its ongoing container operations. At June 30,
        1999, 91% of the original equipment remained in the Registrant's fleet,
        as compared to 95% at December 31, 1998, and was comprised of the
        following:


<TABLE>
<CAPTION>
                                                           40-Foot
                                 20-Foot      40-Foot     High-Cube
                                  -----        -----        -----
<S>                              <C>          <C>         <C>
Containers on lease:
     Term leases                    440          204           18
     Master leases                2,264          558           56
                                  -----        -----        -----
        Subtotal                  2,704          762           74

Containers off lease                978          256           12
                                  -----        -----        -----

     Total container fleet        3,682        1,018           86
                                  =====        =====        =====
</TABLE>


<TABLE>
<CAPTION>
                                                                                                   40-Foot
                                             20-Foot                     40-Foot                   High-Cube
                                        ------------------         ------------------         ------------------
                                        Units          %           Units          %           Units          %
                                        -----        -----         -----        -----         -----        -----
<S>                                     <C>          <C>           <C>          <C>           <C>          <C>
Total purchases                         4,000          100%        1,150          100%          100          100%
    Less disposals                        318            8%          132           11%           14           14%
                                        -----        -----         -----        -----         -----        -----

Remaining fleet at June 30, 1999        3,682           92%        1,018           89%           86           86%
                                        =====        =====         =====        =====         =====        =====
</TABLE>


        At June 30, 1999, the Registrant had $566,919 in cash and cash
        equivalents, a decrease of $86,932 from the December 31, 1998 cash
        balances. Net lease receivables at June 30, 1999 decreased 35% when
        compared to December 31, 1998.

        The Registrant's cash distribution from operations for the second
        quarter of 1999 was 6.0% (annualized) of the limited partners' original
        capital contribution, a decline from the first quarter of 1999
        distribution of 6.5% (annualized). These distributions are directly
        related to the Registrant's results from operations and may fluctuate
        accordingly. The cash distribution from sales proceeds for the second
        quarter of 1999 was 2.25% (annualized) of the limited partners' original
        capital contribution, a decline from the first quarter of 1999 of 3.00%
        (annualized). Sales proceeds distributed to the limited partners may
        fluctuate in subsequent periods, reflecting the level of container
        disposals.

        The sentiment with respect to the container industry's slump over the
        past two years has turned more favorable in recent months as evidence
        suggests a turnaround is underway with respect to Asia's economic
        crisis. In recent months, economic reforms in Asia, as well as in Latin
        America, have begun to produce gradual improvement in terms of world
        trade, and there are preliminary indications that containerized trade
        volumes from North America and Europe to Asia, in particular, may be
        stabilizing. In addition, intra-Asian trade, which also has stagnated
        since the



                                       10
<PAGE>   11

        Asia financial crisis began nearly two years ago, has shown increased
        activity in recent months. These favorable signs, however, have yet to
        produce any significant positive impact on the Registrant's operating
        performance. In spite of the reduced redelivery of on-hire equipment by
        the ocean carriers, per-diem rental rates, which declined sharply over
        the past two years, have continued to soften as a result of competitive
        market conditions, decreased demand and high inventories.

        The Registrant continues to take advantage of its strong marketing
        resources in order to seek out leasing opportunities during this period
        in which seasonal factors are also influencing the increased demand. At
        the same time, it has identified specific strategies intended to
        strengthen on-hire volumes and enhance utilization of the container
        fleet. The short-term objective is to improve utilization by offering
        greater leasing incentives and actively moving surplus, off-hire
        equipment to higher-demand locations. While this short-term strategy
        will increase repositioning expenses, it may also minimize those
        expenses related to handling and storing off-hire containers. These
        measures will also provide the longer-term advantage of placing the
        containers where the demand is greatest.


2)      Material changes in the results of operations between the three and
        six-month periods ended June 30, 1999 and the three and six-month
        periods ended June 30, 1998.

        Net lease revenue for the three and six-month periods ended June 30,
        1999 was $227,987 and $503,588, respectively, a decrease of
        approximately 36% and 27%, respectively, from the same periods in the
        prior year. Gross rental revenue (a component of net lease revenue) for
        the three and six-month periods ended June 30, 1999 was $422,429 and
        $885,169, respectively, a decline of 23% and 20 from the same respective
        periods in the prior year. Gross rental revenue was primarily impacted
        by lower per-diem rental rates. Average per-diem rental rates declined
        6% for both the three and six-month periods ended June 30, 1999 when
        compared to the same periods in the prior year. The Registrant's average
        fleet size and utilization rates for the three and six-month periods
        ended June 30, 1999 and 1998 were as follows:

<TABLE>
<CAPTION>
                                                      Three Months Ended           Six Months Ended
                                                      ------------------           ----------------
                                                    June 30,      June 30,      June 30,      June 30,
                                                      1999          1998          1999          1998
                                                      ----          ----          ----          ----
        <S>                                         <C>           <C>           <C>           <C>
        Average fleet size (measured in
           twenty-foot equivalent units (TEU))        5,954         6,351         6,026         6,384
        Average Utilization                              71%           81%           71%           80%
</TABLE>

        Rental equipment operating expenses were 33% and 30%, respectively, of
        the Registrant's gross lease revenue during the three and six-month
        periods ended June 30, 1999, as compared to 23% and 25%, respectively,
        of the Registrant's gross lease revenue during the three and six-month
        periods ended June 30, 1998.

        Year 2000

        The Registrant relies upon the financial and operational systems
        provided by the Leasing Company and its affiliates, as well as the
        systems provided by other independent third parties to service the three
        primary areas of its business: investor processing/maintenance;
        container leasing/asset tracking; and accounting finance. The Leasing
        Company's computer systems have undergone modifications in order to
        render the systems ready for the Year 2000. The Leasing Company has
        completed a detailed inventory of all software and hardware systems and
        has identified all components that need to be modified. The Leasing
        Company has completed all the necessary changes and testing in a
        dedicated Year 2000 environment. The Leasing Company anticipates that
        all compliant code will be live by the end of August 1999. The Leasing
        Company has contacted all of its critical business suppliers and has
        been advised that their systems are Year 2000 compliant. The Leasing
        Company has also confirmed the compliance of its suppliers' products
        through its own extensive testing. Expenses associated with addressing
        Year 2000 issues are being recognized as incurred. Management has not
        yet assessed the Year 2000 compliance expense but does not anticipate
        the costs incurred to date or to be incurred in the future by the
        Leasing Company and its affiliates to be in excess of



                                       11
<PAGE>   12

        $500,000. None of the costs incurred with respect to Year 2000
        compliance will be borne by the Registrant. The Leasing Company believes
        it will be able to resolve any major Year 2000 issues. The Leasing
        Company is aware of the implications of a Year 2000 computer system
        failure and is currently in the process of developing its contingency
        plans. While management believes the possibility of a Year 2000 system
        failure to be remote, if the Leasing Company's internal systems or those
        of its critical business suppliers fail, the Leasing Company's
        consolidated financial position, liquidity or results of operations may
        be adversely affected.

        Cautionary Statement

        This Quarterly Report on Form 10-Q contains statements relating to
        future results of the Registrant, including certain projections and
        business trends, that are "forward-looking statements" as defined in the
        Private Securities Litigation Reform Act of 1995. Actual results may
        differ materially from those projected as a result of certain risks and
        uncertainties, including but not limited to changes in: economic
        conditions; trade policies; demand for and market acceptance of leased
        marine cargo containers; competitive utilization and per-diem rental
        rate pressures; as well as other risks and uncertainties, including but
        not limited to those described in the above discussion of the marine
        container leasing business under Item 2., Management's Discussion and
        Analysis of Financial Condition and Results of Operations; and those
        detailed from time to time in the filings of Registrant with the
        Securities and Exchange Commission.


Item 3. Quantitative and Qualitative Disclosures About Market Risk

        Not applicable.



                                       12
<PAGE>   13

                           PART II - OTHER INFORMATION


Item 1. Legal Proceedings

        As the Registrant has previously reported, in February 1997, its former
        outside auditors, Arthur Andersen LLP ("Arthur Andersen"), resigned as
        auditors to The Cronos Group (the "Parent Company"), its subsidiaries,
        and all other entities affiliated with the Parent Company, including the
        Registrant. The Parent Company is the indirect corporate parent of CCC,
        the managing general partner of the Registrant. CCC does not believe,
        based upon the information currently available to it, that Arthur
        Andersen's resignation was triggered by any concern over the accounting
        policies and procedures followed by the Registrant.

        Arthur Andersen's reports on the financial statements of CCC and the
        Registrant, for years preceding 1996, had not contained an adverse
        opinion or a disclaimer of opinion, nor were any such reports qualified
        or modified as to uncertainty, audit scope, or accounting principles.

        During the Registrant's fiscal year ended December 31, 1995, and the
        subsequent interim period preceding Arthur Andersen's resignation, there
        were no disagreements between CCC or the Registrant and Arthur Andersen
        on any matter of accounting principles or practices, financial statement
        disclosure, or auditing scope or procedure.

        In connection with its resignation, Arthur Andersen prepared a report
        pursuant to Section 10A of the Securities Exchange Act of 1934, as
        amended, for filing by the Parent Company with the Securities and
        Exchange Commission ("SEC"). As a result of the Arthur Andersen report,
        the SEC commenced an investigation of the Parent Company on February 10,
        1997. The purpose of the investigation has been to determine whether the
        Parent Company and persons associated with the Parent Company violated
        the federal securities laws administered by the SEC. The Registrant does
        not believe that the focus of the SEC's investigation is upon the
        Registrant or CCC.

        Current management of the Parent Company has been in discussions with
        the staff of the SEC with a view to settling the investigation. The
        Parent Company is hopeful of reaching a settlement of the investigation
        by the end of 1999.


Item 3. Defaults Upon Senior Securities

        See Item 5. Other Information.


Item 5. Other Information

        In 1993, the Parent Company negotiated a credit facility with several
        banks for the use by the Parent Company and its subsidiaries, including
        CCC. At December 31, 1998, approximately $33,110,000 in principal
        indebtedness was outstanding under that credit facility (none of which
        had been borrowed by the Registrant). As a party to that credit
        facility, CCC was jointly and severally liable for the repayment of all
        principal and interest owed under the credit facility. On August 2,
        1999, all outstanding amounts under the credit facility were repaid
        through the establishment of a new credit facility with two financial
        institutions. CCC is not a party to the new loan agreement. The Parent
        Company has guaranteed up to $10 million of amounts borrowed under the
        new credit facility and, as partial security for this guarantee, the
        Parent Company has pledged all of the capital stock held by it in Cronos
        Holding/Investments (U.S.), Inc., a Delaware corporation that, in turn,
        owns all of the outstanding capital stock of CCC.

        The Registrant is not a borrower under the new credit facility
        established by the Parent Company, and neither the containers nor the
        other assets of the Registrant have been pledged as collateral under the
        new credit facility.



                                       13
<PAGE>   14

Item 6. Exhibits and Reports on Form 8-K

(a)  Exhibits

<TABLE>
<CAPTION>
      Exhibit
         No.                       Description                                Method of Filing
         ---                       -----------                                ----------------
<S>             <C>                                                           <C>
        3(a)    Limited Partnership Agreement of the                                 *
                Registrant, amended and restated as of November 7, 1989

        3(b)    Certificate of Limited Partnership of the                            **
                Registrant

        27      Financial Data Schedule                                              Filed with this document
</TABLE>


(b)  Reports on Form 8-K

        No reports on Form 8-K were filed by the Registrant during the quarter
ended June 30, 1999.




















----------

*       Incorporated by reference to Exhibit "A" to the Prospectus of the
        Registrant dated November 7, 1989, included as part of Registration
        Statement on Form S-1 (No. 33-30245)

**      Incorporated by reference to Exhibit 3.2 to the Registration Statement
        on Form S-1 (No. 33-30245)



                                       14
<PAGE>   15

                                   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.




                                            IEA INCOME FUND X, L.P.


                                            By   Cronos Capital Corp.
                                                 The General Partner




                                            By /s/ Dennis J. Tietz
                                               ---------------------------------
                                               Dennis J. Tietz
                                               President and Director of
                                               Cronos Capital Corp. ("CCC")
                                               Principal Executive Officer of
                                               CCC




Date:  August 16, 1999



                                       15
<PAGE>   16

                                  EXHIBIT INDEX


<TABLE>
<CAPTION>
      Exhibit
         No.                       Description                                Method of Filing
         ---                       -----------                                ----------------
<S>             <C>                                                           <C>
        3(a)    Limited Partnership Agreement of the                                 *
                Registrant, amended and restated as of November 7, 1989

        3(b)    Certificate of Limited Partnership of the                            **
                Registrant

        27      Financial Data Schedule                                              Filed with this document
</TABLE>









----------

*       Incorporated by reference to Exhibit "A" to the Prospectus of the
        Registrant dated November 7, 1989, included as part of Registration
        Statement on Form S-1 (No. 33-30245)

**      Incorporated by reference to Exhibit 3.2 to the Registration Statement
        on Form S-1 (No. 33-30245)