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                                FORM 10-Q


                    SECURITIES AND EXCHANGE COMMISSION
                         WASHINGTON, D.C.  20549

(Mark One)

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

For the quarterly period ended March 31, 2001

                                    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 0-20299

                SOUTHWEST OIL & GAS 1990-91 INCOME PROGRAM
                Southwest Oil & Gas Income Fund X-C, L.P.
                  (Exact name of registrant as specified
                  in its limited partnership agreement)

Delaware                                75-2374445
(State or other jurisdiction of                (I.R.S. Employer
incorporation or organization)                Identification No.)


                       407 N. Big Spring, Suite 300
                           Midland, Texas 79701
                 (Address of principal executive offices)

                              (915) 686-9927
                      (Registrant's telephone number,
                           including area code)

Indicate  by  check  mark  whether 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

        The total number of pages contained in this report is 13.


                     PART I. - FINANCIAL INFORMATION


Item 1.   Financial Statements

The  unaudited  condensed financial statements included  herein  have  been
prepared  by  the Registrant (herein also referred to as the "Partnership")
in  accordance  with generally accepted accounting principles  for  interim
financial information and with the instructions to Form 10-Q and Rule 10-01
of Regulation S-X.  Accordingly, they do not include all of the information
and  footnotes  required  by generally accepted accounting  principles  for
complete   financial  statements.   In  the  opinion  of  management,   all
adjustments necessary for a fair presentation have been included and are of
a  normal  recurring nature.  The financial statements should  be  read  in
conjunction with the audited financial statements and the notes thereto for
the  year ended December 31, 2000 which are found in the Registrant's  Form
10-K  Report  for  2000 filed with the Securities and Exchange  Commission.
The December 31, 2000 balance sheet included herein has been taken from the
Registrant's 2000 Form 10-K Report.  Operating results for the three  month
period  ended March 31, 2001 are not necessarily indicative of the  results
that may be expected for the full year.


                Southwest Oil & Gas Income Fund X-C, L.P.

                              Balance Sheets


                                                 March 31,    December 31,
                                                    2001          2000
                                                 ---------    ------------
                                                (unaudited)
  Assets

Current assets:
 Cash and cash equivalents                    $     66,522        65,399
 Receivable from Managing General Partner          137,702       112,098
 Distribution receivable                                89             -
                                                 ---------     ---------
    Total current assets                           204,313       177,497
                                                 ---------     ---------
Oil and gas properties - using the
 full-cost method of accounting                  2,412,039     2,411,782
  Less accumulated depreciation,
   depletion and amortization                    2,102,496     2,083,496
                                                 ---------     ---------
    Net oil and gas properties                     309,543       328,286
                                                 ---------     ---------
                                              $    513,856       505,783
                                                 =========     =========

  Liabilities and Partners' Equity

Partners' equity:
 General partners                             $        324       (2,383)
 Limited partners                                  513,532       508,166
                                                 ---------     ---------
                                                   513,856       505,783
                                                 ---------     ---------
    Total partners' equity                    $    513,856       505,783
                                                 =========     =========







                Southwest Oil & Gas Income Fund X-C, L.P.

                         Statements of Operations
                               (unaudited)


                                                        Three Months Ended
                                                            March 31,
                                                          2001      2000
                                                          ----      ----
  Revenues

Oil and gas                                         $   297,930    221,246
Interest                                                    936        458
                                                        -------    -------
                                                        298,866    221,704
                                                        -------    -------
  Expenses

Production                                              136,521    158,363
General and administrative                               10,272     10,427
Depreciation, depletion and amortization                 19,000     13,000
                                                        -------    -------
                                                        165,793    181,790
                                                        -------    -------
Net income                                          $   133,073     39,914
                                                        =======    =======
Net income allocated to:

  Managing General Partner                          $    13,687      4,762
                                                        =======    =======
  General partner                                   $     1,521        529
                                                        =======    =======
  Limited partners                                  $   117,865     34,623
                                                        =======    =======
   Per limited partner unit                         $    18.87       5.54
                                                        =======    =======














                Southwest Oil & Gas Income Fund X-C, L.P.

                         Statements of Cash Flows
                               (unaudited)


                                                        Three Months Ended
                                                            March 31,
                                                          2001      2000
                                                          ----      ----
Cash flows from operating activities:

  Cash from oil and gas sales                       $   276,614    213,197
  Cash paid to suppliers                              (151,081)  (147,605)
  Interest received                                         936        458
                                                        -------    -------
   Net cash provided by operating activities            126,469     66,050
                                                        -------    -------
Cash flows used in investing activities:

  Additions to oil and gas properties                     (257)      (350)
                                                        -------    -------
Cash flows used in financing activities:

  Distributions to partners                           (125,089)   (49,871)
                                                        -------    -------
Net increase in cash and cash equivalents                 1,123     15,829

  Beginning of period                                    65,399     26,435
                                                        -------    -------
  End of period                                     $    66,522     42,264
                                                        =======    =======

                                                               (continued)













                Southwest Oil & Gas Income Fund X-C, L.P.

                   Statements of Cash Flows, continued
                               (unaudited)


                                                        Three Months Ended
                                                            March 31,
                                                          2001      2000
                                                          ----      ----
Reconciliation of net income to net cash
  provided by operating activities:

Net income                                          $   133,073     39,914

Adjustments to reconcile net income to net
  cash provided by operating activities:

  Depreciation, depletion and amortization               19,000     13,000
  Increase in receivables                              (21,316)    (8,049)
  (Decrease) increase in payables                       (4,288)     21,185
                                                        -------    -------
Net cash provided by operating activities           $   126,469     66,050
                                                        =======    =======

                Southwest Oil & Gas Income Fund X-C, L.P.
                     (a Delaware limited partnership)

                      Notes to Financial Statements


1.   Organization
     Southwest Oil & Gas Income Fund X-C, L.P. was organized under the laws
     of  the  state of Delaware on September 20, 1991, for the  purpose  of
     acquiring  producing oil and gas properties and to produce and  market
     crude oil and natural gas produced from such  properties for a term of
     50  years, unless terminated at an earlier date as provided for in the
     Partnership  Agreement.   The  Partnership  sells  its  oil  and   gas
     production  to  several purchasers with the prices it  receives  being
     dependent  upon  the oil and gas economy.  Southwest  Royalties,  Inc.
     serves as the Managing General Partner and H. H.  Wommack, III, as the
     individual   general  partner.   Revenues,  costs  and  expenses   are
     allocated as follows:

                                                     Limited      General
                                                     Partners     Partners
                                                     --------     --------
     Interest income on capital contributions        100%            -
     Oil and gas sales                                90%          10%
     All other revenues                               90%          10%
     Organization and offering costs (1)             100%            -
     Syndication costs                               100%            -
     Amortization of organization costs              100%            -
     Property acquisition costs                      100%            -
     Gain/loss on property disposition                90%          10%
     Operating and administrative costs (2)           90%          10%
     Depreciation, depletion and amortization
      of oil and gas properties                      100%            -
     All other costs                                  90%          10%

          (1)   All  organization costs in excess of 3% of initial  capital
          contributions  will be paid by the Managing General  Partner  and
          will  be treated as a capital contribution.  The Partnership paid
          the  Managing  General Partner an amount equal to 3%  of  initial
          capital contributions for such organization costs.

          (2)   Administrative costs in any year which exceed 2% of capital
          contributions shall be paid by the Managing General  Partner  and
          will be treated as a capital contribution.

2.   Summary of Significant Accounting Policies
     The  interim financial information as of March 31, 2001, and  for  the
     three  months ended March 31, 2001, is unaudited.  Certain information
     and  footnote  disclosures normally included in  financial  statements
     prepared  in accordance with generally accepted accounting  principles
     have been condensed or omitted in this Form 10-Q pursuant to the rules
     and  regulations of the Securities and Exchange Commission.   However,
     in  the  opinion  of  management, these interim  financial  statements
     include all the necessary adjustments to fairly present the results of
     the interim periods and all such adjustments are of a normal recurring
     nature.  The interim consolidated financial statements should be  read
     in  conjunction  with the audited financial statements  for  the  year
     ended December 31, 2000.


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

General

Southwest  Oil  &  Gas Income Fund X-C, L.P. was organized  as  a  Delaware
limited  partnership on September 20, 1991.  The offering of  such  limited
partnership  interests began October 1, 1991 as part of  a  shelf  offering
registered  under  the  name Southwest Oil & Gas  1990-91  Income  Program.
Minimum  capital requirements for the Partnership were met on  January  13,
1992, and concluded April 30, 1992.

The  Partnership was formed to acquire interests in producing oil  and  gas
properties,  to produce and market crude oil and natural gas produced  from
such properties, and to distribute the net proceeds from operations to  the
limited  and  general partners.  Net revenues from producing  oil  and  gas
properties will not be reinvested in other revenue producing assets  except
to the extent that production facilities and wells are improved or reworked
or  where methods are employed to improve or enable more efficient recovery
of oil and gas reserves.

Increases   or   decreases   in  Partnership   revenues   and,   therefore,
distributions  to partners will depend primarily on changes in  the  prices
received  for  production,  changes in volumes of  production  sold,  lease
operating  expenses, enhanced recovery projects, offset drilling activities
pursuant  to farm-out arrangements, sales of properties, and the  depletion
of  wells.   Since  wells deplete over time, production  can  generally  be
expected to decline from year to year.

Well  operating costs and general and administrative costs usually decrease
with   production   declines;  however,  these  costs  may   not   decrease
proportionately.  Net income available for distribution to the partners  is
therefore expected to fluctuate in later years based on these factors.

Based on current conditions, management anticipates performing no workovers
during  2001 or 2002 to enhance production.  Workovers may be performed  in
the  year 2003.  The partnership may have an increase in production volumes
the  year 2003, otherwise, the partnership will most likely experience  the
historical production decline of approximately 9% per year.

Oil and Gas Properties

Oil  and  gas  properties  are accounted for at cost  under  the  full-cost
method.  Under this method, all productive and nonproductive costs incurred
in  connection with the acquisition, exploration and development of oil and
gas  reserves  are capitalized.  Gain or loss on the sale of  oil  and  gas
properties  is not recognized unless significant oil and gas  reserves  are
involved.

The  Partnership's policy for depreciation, depletion and  amortization  of
oil  and  gas  properties is computed under the units  of  revenue  method.
Under the units of revenue method, depreciation, depletion and amortization
is  computed  on  the  basis of current gross revenues from  production  in
relation  to future gross revenues, based on current prices, from estimated
production of proved oil and gas reserves.

Should the net capitalized costs exceed the estimated present value of  oil
and gas reserves, discounted at 10%, such excess costs would be charged  to
current  expense.  As of March 31, 2001, the net capitalized costs did  not
exceed the estimated present value of oil and gas reserves.


Results of Operations

A.  General Comparison of the Quarters Ended March 31, 2001 and 2000

The  following  table  provides certain information  regarding  performance
factors for the quarters ended March 31, 2001 and 2000.

                                               Three Months
                                                  Ended         Percentage
                                                March 31,        Increase
                                              2001      2000    (Decrease)
                                              ----      ----    ----------
Average price per barrel of oil           $   25.12     24.87        1%
Average price per mcf of gas              $    7.27      1.76      313%
Oil production in barrels                     7,000     8,000     (13%)
Gas production in mcf                        16,800    12,700       32%
Gross oil and gas revenue                 $ 297,930   221,246       35%
Net oil and gas revenue                   $ 161,409    62,883      157%
Partnership distributions                 $ 125,000    50,000      150%
Limited partner distributions             $ 112,500    45,000      150%
Per unit distribution to limited
 partners                                 $   18.01      7.20      150%
Number of limited partner units               6,246     6,246

Revenues

The  Partnership's oil and gas revenues increased to $297,930 from $221,246
for  the  quarters ended March 31, 2001 and 2000, respectively, an increase
of  35%.   The  principal factors affecting the comparison of the  quarters
ended March 31, 2001 and 2000 are as follows:

1.  The  average  price  for a barrel of oil received  by  the  Partnership
    increased  during the quarter ended March 31, 2001 as compared  to  the
    quarter ended March 31, 2000 by 1%, or $.25 per barrel, resulting in an
    increase of approximately $1,800 in revenues. Oil sales represented 59%
    of  total oil and gas sales during the quarter ended March 31, 2001  as
    compared to 90% during the quarter ended March 31, 2000.

    The  average  price  for  an  mcf of gas received  by  the  Partnership
    increased  during the same period by 313%, or $5.51 per mcf,  resulting
    in an increase of approximately $92,600 in revenues.

    The  total  increase in revenues due to the change in  prices  received
    from oil and gas production is approximately $94,400.  The market price
    for  oil  and gas has been extremely volatile over the past decade  and
    management  expects a certain amount of volatility to continue  in  the
    foreseeable future.


2.  Oil  production decreased approximately 1,000 barrels or 13% during the
    quarter ended March 31, 2001 as compared to the quarter ended March 31,
    2000, resulting in a decrease of approximately $24,900 in revenues.

    Gas production increased approximately 4,100 mcf or 32% during the same
    period, resulting in an increase of approximately $7,200 in revenues.

    The  net total decrease in revenues due to the change in production  is
    approximately  $17,700.  The increase in gas production  is  due  to  a
    successful  low cost workover performed on a non-operated lease  during
    2000.

Costs and Expenses

Total  costs  and  expenses decreased to $165,793  from  $181,790  for  the
quarters  ended  March 31, 2001 and 2000, respectively, a decrease  of  9%.
The  decrease is the result of lower lease operating costs and general  and
administrative  expense,  partially offset  by  an  increase  in  depletion
expense.

1.  Lease  operating  costs  and  production  taxes  were  14%  lower,   or
    approximately $21,800 less during the quarter ended March 31,  2001  as
    compared to the quarter ended March 31, 2000.

2.  General and administrative costs consist of independent accounting  and
    engineering  fees,  computer services, postage,  and  Managing  General
    Partner personnel costs.  General and administrative costs decreased 1%
    or  approximately  $200  during the quarter ended  March  31,  2001  as
    compared to the quarter ended March 31, 2000.

3.  Depletion expense increased to $19,000 for the quarter ended March  31,
    2001  from  $13,000  for the same period in 2000.  This  represents  an
    increase  of 46%.  Depletion is calculated using the units  of  revenue
    method  of  amortization based on a percentage of current period  gross
    revenues  to  total future gross oil and gas revenues, as estimated  by
    the  Partnership's  independent  petroleum  consultants.   Contributing
    factors  to  the increase in depletion expense between the  comparative
    periods  were  a  increase in the price of oil used  to  determine  the
    Partnerships reserves and the increase in oil and gas sales.


Liquidity and Capital Resources

The  primary source of cash is from operations, the receipt of income  from
interests in oil and gas properties.  The Partnership knows of no  material
change, nor does it anticipate any such change.

Cash flows provided by operating activities were approximately $126,500  in
the  quarter ended March 31, 2001 as compared to approximately  $66,100  in
the quarter ended March 31, 2000.  The primary source of the 2001 cash flow
from operating activities was profitable operations.

Cash  flows  used in investing activities were approximately  $300  in  the
quarter  ended  March  31, 2001 as compared to approximately  $350  in  the
quarter ended March 31, 2000.  The principle use of the 2001 cash flow from
investing activities was the additions of oil and gas properties.

Cash flows used in financing activities were approximately $125,100 in  the
quarter  ended March 31, 2001 as compared to approximately $49,900  in  the
quarter ended March 31, 2000.  The only use in financing activities was the
distributions to partners.

Total  distributions during the quarter ended March 31, 2001 were  $125,000
of  which  $112,500 was distributed to the limited partners and $12,500  to
the general partners.  The per unit distribution to limited partners during
the  quarter  ended March 31, 2001 was $18.01.  Total distributions  during
the  quarter  ended  March  31,  2000 were $50,000  of  which  $45,000  was
distributed  to  the limited partners and $5,000 to the  general  partners.
The  per  unit  distribution to limited partners during the  quarter  ended
March 31, 2000 was $7.20.

The  sources  for  the  2001 distributions of $125,000  were  oil  and  gas
operations  of  approximately  $126,500,  resulting  in  excess  cash   for
contingencies or subsequent distributions to partners.  The sources for the
2000  distributions of $50,000 were oil and gas operations of approximately
$66,100  and the change of oil and gas properties of approximately  $(350),
resulting  in excess cash for contingencies or subsequent distributions  to
partners.

Since  inception of the Partnership, cumulative monthly cash  distributions
of  $3,439,322  have  been made to the partners.  As  of  March  31,  2001,
$3,114,218 or $498.59 per limited partner unit has been distributed to  the
limited partners, representing a 100% return of the capital contributed.

As of March 31, 2001, the Partnership had approximately $204,300 in working
capital.   The  Managing  General Partner knows of no  unusual  contractual
commitments  and  believes  the  revenues  generated  from  operations  are
adequate to meet the needs of the Partnership.

Item 3.   Quantitative and Qualitative Disclosures About Market Risk

The  Partnership  is  not a party to any derivative or embedded  derivative
instruments.



                       PART II. - OTHER INFORMATION


Item 1.   Legal Proceedings

          None

Item 2.   Changes in Securities

          None

Item 3.   Defaults Upon Senior Securities

          None

Item 4.   Submission of Matter to a Vote of Security Holders

          None

Item 5.   Other Information

          None

Item 6.   Exhibits and Reports on Form 8-K

               (a)  Reports on Form 8-K:

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


                                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.


                              SOUTHWEST OIL & GAS
                              INCOME FUND X-C, L.P.
                              a Delaware limited partnership


                              By:  Southwest Royalties, Inc.
                                   Managing General Partner


                              By:  /s/ Bill E. Coggin
                                   ------------------------------
                                   Bill E. Coggin, Vice President
                                   and Chief Financial Officer



Date:  May 15, 2001