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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, 1998

                                    OR

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

For the transition period from ________________ to ________________


Commission file number 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, 1997 which are found in the Registrant's  Form
10-K  Report  for  1997 filed with the Securities and Exchange  Commission.
The December 31, 1997 balance sheet included herein has been taken from the
Registrant's 1997 Form 10-K Report.  Operating results for the three  month
period  ended March 31, 1998 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,
                                                    1998          1997
                                                 ---------    ------------
                                                (unaudited)
  Assets

Current assets:
 Cash and cash equivalents                    $      5,558         9,123
 Receivable from Managing General Partner           93,228       140,208
 Other Receivable                                        -         1,700
                                                 ---------     ---------
    Total current assets                            98,786       151,031
                                                 ---------     ---------
Oil and gas properties - using the
 full-cost method of accounting                  2,419,881     2,418,082
  Less accumulated depreciation,
   depletion and amortization                    1,826,496     1,798,496
                                                 ---------     ---------
    Net oil and gas properties                     593,385       619,586
                                                 ---------     ---------
                                              $    692,171       770,617
                                                 =========     =========

  Liabilities and Partners' Equity

Current liabilities:
 Accounts payable                             $      7,954             -
 Distributions payable                                 285           116
                                                 ---------     ---------
    Total current liabilities                        8,239           116
                                                 ---------     ---------
Partners' equity:
 General partners                                 (12,088)       (6,231)
 Limited partners                                  696,020       776,732
                                                 ---------     ---------
    Total partners' equity                         683,932       770,501
                                                 ---------     ---------
                                              $    692,171       770,617
                                                 =========     =========







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

                         Statements of Operations
                               (unaudited)


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

Oil and gas                                         $   202,161    336,342
Interest                                                    434      1,714
                                                        -------    -------
                                                        202,595    338,056
                                                        -------    -------
  Expenses

Production                                              159,104    163,984
General and administrative                               17,060     16,319
Depreciation, depletion and amortization                 28,000     29,000
                                                        -------    -------
                                                        204,164    209,303
                                                        -------    -------
Net income (loss)                                   $   (1,569)    128,753
                                                        =======    =======
Net income (loss) allocated to:

 Managing General Partner                           $     2,379     14,198
                                                        =======    =======
  General partner                                   $       264      1,577
                                                        =======    =======
  Limited partners                                  $   (4,212)    112,978
                                                        =======    =======
   Per limited partner unit                         $     (.67)      18.09
                                                        =======    =======














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

                         Statements of Cash Flows
                               (unaudited)


                                                        Three Months Ended
                                                            March 31,
                                                          1998      1997
                                                          ----      ----
Cash flows from operating activities:

  Cash from oil and gas sales                       $   261,878    386,915
  Cash paid to suppliers                              (179,247)  (192,072)
  Interest received                                         434      1,714
                                                        -------    -------
   Net cash provided by operating activities             83,065    196,557
                                                        -------    -------
Cash flows from investing activities:

  Additions to oil and gas properties                   (4,034)    (1,834)
  Sale of oil and gas properties                          2,235      1,787
                                                        -------    -------
   Net cash used in investing activities                (1,799)       (47)
                                                        -------    -------
Cash flows used in financing activities:

  Distributions to partners                            (84,831)  (191,517)
                                                        -------    -------
Net (decrease) increase in cash and cash
 equivalents                                            (3,565)      4,993

  Beginning of period                                     9,123    207,773
                                                        -------    -------
  End of period                                     $     5,558    212,766
                                                        =======    =======

                                                               (continued)













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

                   Statements of Cash Flows, continued
                               (unaudited)


                                                        Three Months Ended
                                                            March 31,
                                                          1998      1997
                                                          ----      ----
Reconciliation of net income to net
 cash provided by operating activities:

Net income (loss)                                   $   (1,569)    128,753

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

  Depreciation, depletion and amortization               28,000     29,000
  Decrease in receivables                                59,717     50,573
  Decrease in payables                                  (3,083)   (11,769)
                                                        -------    -------
Net cash provided by operating activities           $    83,065    196,557
                                                        =======    =======

                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, 1998, and  for  the
     three  months ended March 31, 1998, 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, 1997.


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  workovers
during  the  next  few years to enhance production.  The Partnership  could
possibly  experience  the  following changes; a  little  less  than  normal
decline in 1998 and thereafter, experience a low decline.


Results of Operations

A.  General Comparison of the Quarters Ended March 31, 1998 and 1997

The  following  table  provides certain information  regarding  performance
factors for the quarters ended March 31, 1998 and 1997.

                                               Three Months
                                                  Ended         Percentage
                                                March 31,        Increase
                                              1998      1997    (Decrease)
                                              ----      ----    ----------
Average price per barrel of oil           $   12.04     22.33     (46%)
Average price per mcf of gas              $    2.26      2.88     (22%)
Oil production in barrels                    11,300    10,900        4%
Gas production in mcf                        29,300    32,300      (9%)
Gross oil and gas revenue                 $ 202,161   336,342     (40%)
Net oil and gas revenue                   $  43,057   172,358     (75%)
Partnership distributions                 $  85,000   191,500     (56%)
Limited partner distributions             $  76,500   172,350     (56%)
Per unit distribution to limited
 partners                                 $   12.25     27.59     (56%)
Number of limited partner units               6,246     6,246

Revenues

The  Partnership's oil and gas revenues decreased to $202,161 from $336,342
for the quarters ended March 31, 1998 and 1997, respectively, a decrease of
40%.   The principal factors affecting the comparison of the quarters ended
March 31, 1998 and 1997 are as follows:

1.  The  average  price  for a barrel of oil received  by  the  Partnership
    decreased  during the quarter ended March 31, 1998 as compared  to  the
    quarter ended March 31, 1997 by 46%, or $10.29 per barrel, resulting in
    a   decrease  of  approximately  $112,200  in  revenues.    Oil   sales
    represented  67%  of total oil and gas sales during the  quarter  ended
    March  31,  1998 as compared to 72% during the quarter ended March  31,
    1997.

    The  average  price  for  an  mcf of gas received  by  the  Partnership
    decreased during the same period by 22%, or $.62 per mcf, resulting  in
    a decrease of approximately $20,000 in revenues.

    The  total  decrease in revenues due to the change in  prices  received
    from  oil  and  gas production is approximately $132,200.   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 increased approximately 400 barrels or  4%  during  the
    quarter ended March 31, 1998 as compared to the quarter ended March 31,
    1997, resulting in an increase of approximately $4,800 in revenues.

    Gas  production decreased approximately 3,000 mcf or 9% during the same
    period, resulting in a decrease of approximately $6,800 in revenues.

    The  net total decrease in revenues due to the change in production  is
    approximately $2,000.

Costs and Expenses

Total  costs  and  expenses decreased to $204,164  from  $209,303  for  the
quarters  ended  March 31, 1998 and 1997, respectively, a decrease  of  2%.
The  decrease  is the result of lower lease operating costs  and  depletion
expense, offset by an increase in general and administrative expense.

1.  Lease   operating  costs  and  production  taxes  were  3%  lower,   or
    approximately $4,900 less during the quarter ended March  31,  1998  as
    compared to the quarter ended March 31, 1997.

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 increased 5%
    or  approximately  $700  during the quarter ended  March  31,  1998  as
    compared to the quarter ended March 31, 1997.

3.  Depletion expense decreased to $28,000 for the quarter ended March  31,
    1998  from  $29,000  for the same period in 1997.   This  represents  a
    decrease  of  3%.  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.


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 $83,100  in
the  quarter ended March 31, 1998 as compared to approximately $196,600  in
the quarter ended March 31, 1997.  The primary source of the 1998 cash flow
from operating activities was profitable operations.

Cash  flows used in investing activities were approximately $1,800  in  the
quarter  ended  March  31,  1998 as compared to approximately  $50  in  the
quarter ended March 31, 1997.  The principle use of the 1998 cash flow from
investing activities was the additions to oil and gas properties, partially
offset by the sale of oil and gas properties.

Cash  flows used in financing activities were approximately $85,000 in  the
quarter ended March 31, 1998 as compared to approximately $191,500  in  the
quarter ended March 31, 1997.  The only use in financing activities was the
distributions to partners.

Total distributions during the quarter ended March 31, 1998 were $85,000 of
which  $76,500  was distributed to the limited partners and $8,500  to  the
general partners.  The per unit distribution to limited partners during the
quarter  ended March 31, 1998 was $12.25.  Total distributions  during  the
quarter  ended  March  31,  1997  were  $191,500  of  which  $172,350   was
distributed  to  the limited partners and $19,150 to the general  partners.
The  per  unit  distribution to limited partners during the  quarter  ended
March 31, 1997 was $27.59.

The  sources  for  the  1998  distributions of $85,000  were  oil  and  gas
operations  of approximately $83,100 and the sale of oil and gas properties
of  approximately $2,200, offset by additions to oil and gas properties  of
approximately $4,000, with the balance from available cash on hand  at  the
beginning  of  the  period.   The sources for  the  1997  distributions  of
$191,500 were oil and gas operations of approximately $196,600 and the sale
of  oil and gas properties of approximately $1,800, offset by additions  to
oil  and  gas properties of approximately $1,800, resulting in excess  cash
for contingencies or subsequent distributions.

Since  inception of the Partnership, cumulative monthly cash  distributions
of  $2,821,318  have  been made to the partners.  As  of  March  31,  1998,
$2,556,194 or $409.25 per limited partner unit has been distributed to  the
limited partners, representing a 82% return of the capital contributed.

As  of March 31, 1998, the Partnership had approximately $90,500 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.


                       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)  Exhibits:

               27  Financial Data Schedule

               (b)  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, 1998