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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 June 30, 1998

                                    OR

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

For the transition period from ________________ to ________________

Commission file number 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 14.


                     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  and
six month periods ended June 30, 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


                                                 June 30,      December 31,
                                                   1998            1997
                                                ---------      ------------
                                               (unaudited)
  Assets

Current assets:
 Cash and cash equivalents                   $      7,111           9,123
 Receivable from Managing General Partner          70,300         140,208
 Other receivable                                       -           1,700
                                                ---------       ---------
    Total current assets                           77,411         151,031
                                                ---------       ---------
Oil and gas properties - using the
 full cost method of accounting                 2,422,171       2,418,082
  Less accumulated depreciation,
   depletion and amortization                   1,857,496       1,798,496
                                                ---------       ---------
    Net oil and gas properties                    564,675         619,586
                                                ---------       ---------
                                             $    642,086         770,617
                                                =========       =========
  Liabilities and Partners' Equity

Current liability - Distributions payable    $        207             116
                                                ---------       ---------
Partners' equity:
 General partners                                (13,193)         (6,231)
 Limited partners                                 655,072         776,732
                                                ---------       ---------
    Total partners' equity                        641,879         770,501
                                                ---------       ---------
                                             $    642,086         770,617
                                                =========       =========



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

                         Statements of Operations
                               (unaudited)


                                 Three Months Ended      Six Months Ended
                                       June 30,              June 30,
                                    1998      1997        1998      1997

  Revenues

Oil and gas                   $   168,362    292,075    370,523    628,416
Interest                              397      1,950        831      3,664
                                  -------    -------    -------    -------
                                  168,759    294,025    371,354    632,080
                                  -------    -------    -------    -------

  Expenses

Production                        131,472    163,474    290,576    327,458
General and administrative         12,340      9,470     29,400     25,788
Depreciation, depletion and
 amortization                      31,000     26,000     59,000     55,000
                                  -------    -------    -------    -------
                                  174,812    198,944    378,976    408,246
                                  -------    -------    -------    -------
Net income (loss)             $   (6,053)     95,081    (7,622)    223,834
                                  =======    =======    =======    =======
Net income (loss) allocated to:

 Managing General Partner     $     2,245     10,897      4,624     25,095
                                  =======    =======    =======    =======
 General Partner              $       250      1,211        514      2,788
                                  =======    =======    =======    =======
 Limited Partners             $   (8,548)     82,973   (12,760)    195,951
                                  =======    =======    =======    =======
  Per limited partner unit    $    (1.37)      13.28     (2.04)      31.37
                                  =======    =======    =======    =======


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

                         Statements of Cash Flows
                               (unaudited)


                                                        Six Months Ended
                                                             June 30,
                                                          1998      1997

Cash flows from operating activities:

 Cash received from sale of oil and gas             $   454,363    694,625
 Cash paid to suppliers                               (333,908)  (362,668)
 Interest received                                          831      3,664
                                                        -------    -------
  Net cash provided by operating activities             121,286    335,621
                                                        -------    -------
Cash flows from investing activities:

 Additions to oil and gas properties                    (4,089)    (8,313)
 Cash received from sale of oil and gas
  properties                                              1,700      2,690
                                                        -------    -------
  Net cash used in investing activities:                (2,389)    (5,623)
                                                        -------    -------
Cash flows used in financing activities:

 Distributions to partners                            (120,909)  (379,501)
                                                        -------    -------
Net decrease in cash and cash equivalents               (2,012)   (49,503)

 Beginning of period                                      9,123    207,773
                                                        -------    -------
 End of period                                      $     7,111    158,270
                                                        =======    =======
                                                               (continued)


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

                   Statements of Cash Flows, continued
                               (unaudited)

                                                        Six Months Ended
                                                             June 30,
                                                          1998      1997
Reconciliation of net income (loss) to net
 cash provided by operating activities:

Net income (loss)                                   $   (7,622)    223,834

Adjustments to reconcile net income (loss) to
 net cash provided by operating activities:

  Depreciation, depletion and amortization               59,000     55,000
  Decrease in receivables                                83,840     66,209
  Decrease in payables                                 (13,932)    (9,422)
                                                        -------    -------
Net cash provided by operating activities           $   121,286    335,621
                                                        =======    =======


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  the  offering  concluded on April 30, 1992  with  total  limited
partner contributions of $3,123,000.

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 farmout 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 does not  anticipate  performing
workovers  in  1998.   The  Partnership could  possibly  experience  a  low
decline.

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 June 30, 1998, the net capitalized costs  did  not
exceed  the  estimated  present value of  the  oil  and  gas  reserves.   A
continuation of the oil price environment experienced during the first half
of 1998 will have an adverse affect on the Company's revenues and operating
cash flow.  Also, further declines in oil prices could result in additional
decreases in the carrying value of the Company's oil and gas properties.





Results of Operations

A.  General Comparison of the Quarters Ended June 30, 1998 and 1997

The  following  table  provides certain information  regarding  performance
factors for the quarters ended June 30, 1998 and 1997:

                                               Three Months
                                                  Ended          Percentage
                                                 June 30,         Increase
                                              1998       1997    (Decrease)
                                              ----       ----    ----------

Average price per barrel of oil          $    11.28     18.00    (37%)
Average price per mcf of gas             $     1.62      2.05    (21%)
Oil production in barrels                    11,200    12,300     (9%)
Gas production in mcf                        25,900    34,500    (25%)
Gross oil and gas revenue                $  168,362   292,075    (42%)
Net oil and gas revenue                  $   36,890   128,601    (71%)
Partnership distributions                $   36,000   188,000    (81%)
Limited partner distributions            $   32,400   169,200    (81%)
Per unit distribution to limited
 partners                                $     5.19     27.09    (81%)
Number of limited partner units               6,246     6,246

Revenues

The  Partnership's oil and gas revenues decreased to $168,362 from $292,075
for the quarters ended June 30, 1998 and 1997, respectively, a decrease  of
42%.   The principal factors affecting the comparison of the quarters ended
June 30, 1998 and 1997 are as follows:

1.  The  average  price  for a barrel of oil received  by  the  Partnership
    decreased  during the quarter ended June 30, 1998 as  compared  to  the
    quarter ended June 30, 1997 by 37%, or $6.72 per barrel, resulting in a
    decrease  of  approximately $82,700 in revenues.  Oil sales represented
    75%  of total oil and gas sales during the quarter ended June 30,  1998
    as compared to 76% during the quarter ended June 30, 1997.

    The  average  price  for  an  mcf of gas received  by  the  Partnership
    decreased during the same period by 21%, or $.43 per mcf, resulting  in
    a decrease of approximately $14,800 in revenues.

    The  total  decrease in revenues due to the change in  prices  received
    from oil and gas production is approximately $97,500.  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 1,100 barrels or 9% during  the
    quarter  ended June 30, 1998 as compared to the quarter ended June  30,
    1997, resulting in a decrease of approximately $12,400 in revenues.

    Gas production decreased approximately 8,600 mcf or 25% during the same
    period, resulting in a decrease of approximately $13,900 in revenues.

    The  total  decrease  in revenues due to the change  in  production  is
    approximately  $26,300.  The decrease in production is due  to  natural
    decline.

Costs and Expenses

Total  costs  and  expenses decreased to $174,812  from  $198,944  for  the
quarters  ended  June 30, 1998 and 1997, respectively, a decrease  of  12%.
The  decrease  is  the result of lower lease operating  expense,  partially
offset by an increase in general and administrative and depletion expense.

1.  Lease  operating  costs  and  production  taxes  were  20%  lower,   or
    approximately $32,000 less during the quarter ended June  30,  1998  as
    compared to the quarter ended June 30, 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
    30%  or approximately $2,900 during the quarter ended June 30, 1998  as
    compared  to the quarter ended June 30, 1997.  Increase in general  and
    administrative costs are the result of higher accounting  fees  due  to
    the  necessity of contracting out preparation of tax depletion and  K-1
    schedules.

3.  Depletion expense increased to $31,000 for the quarter ended  June  30,
    1998  from  $26,000  for the same period in 1997.  This  represents  an
    increase  of 19%.  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 the decrease in the price of oil and gas used to determine
    the Partnership's reserves for January 1, 1998 as compared to 1997.


B.   General  Comparison of the Six Month Periods Ended June 30,  1998  and
1997

The  following  table  provides certain information  regarding  performance
factors for the six month periods ended June 30, 1998 and 1997:

                                                Six Months
                                                  Ended          Percentage
                                                 June 30,         Increase
                                              1998       1997    (Decrease)
                                              ----       ----    ----------

Average price per barrel of oil          $    11.66     19.70    (41%)
Average price per mcf of gas             $     1.96      2.40    (18%)
Oil production in barrels                    22,500    23,600     (5%)
Gas production in mcf                        55,200    68,100    (19%)
Gross oil and gas revenue                $  370,523   628,416    (41%)
Net oil and gas revenue                  $   79,947   300,958    (73%)
Partnership distributions                $  121,000   379,500    (68%)
Limited partner distributions            $  108,900   341,550    (68%)
Per unit distribution to limited
 partners                                $    17.44     54.68    (68%)
Number of limited partner units               6,246     6,246

Revenues

The  Partnership's oil and gas revenues decreased to $370,523 from $628,416
for  the  six months ended June 30, 1998 and 1997, respectively, a decrease
of  41%.  The principal factors affecting the comparison of the six  months
ended June 30, 1998 and 1997 are as follows:

1.  The  average  price  for a barrel of oil received  by  the  Partnership
    decreased during the six months ended June 30, 1998 as compared to  the
    six  months ended June 30, 1997 by 41%, or $8.04 per barrel,  resulting
    in  a  decrease  of  approximately $189,700  in  revenues.   Oil  sales
    represented 71% of total oil and gas sales during the six months  ended
    June  30, 1998 as compared to 74% during the six months ended June  30,
    1997.

    The  average  price  for  an  mcf of gas received  by  the  Partnership
    decreased during the same period by 18%, or $.44 per mcf, resulting  in
    a decrease of approximately $30,000 in revenues.

    The  total  decrease in revenues due to the change in  prices  received
    from  oil  and  gas production is approximately $219,700.   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 1,100 barrels or 5% during  the
    six months ended June 30, 1998 as compared to the six months ended June
    30, 1997, resulting in a decrease of approximately $12,800 in revenues.

    Gas  production  decreased approximately 12,900 mcf or 19%  during  the
    same  period,  resulting  in  a decrease of  approximately  $25,300  in
    revenues.

    The  total  decrease  in revenues due to the change  in  production  is
    approximately $38,100.

Costs and Expenses

Total  costs and expenses decreased to $378,976 from $408,246 for  the  six
months  ended June 30, 1998 and 1997, respectively, a decrease of 7%.   The
decrease  is  the  result of a decline in lease operating costs,  partially
offset  by  an increase in general and administrative expense and depletion
expense.

1.  Lease  operating  costs  and  production  taxes  were  11%  lower,   or
    approximately $36,900 less during the six months ended June 30, 1998 as
    compared to the six months ended June 30, 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
    14%  or approximately $3,600 during the six months ended June 30,  1998
    as compared to the six months ended June 30, 1997.

3.  Depletion  expense increased to $59,000 for the six months  ended  June
    30, 1998 from $55,000 for the same period in 1997.  This represents  an
    increase  of  7%.  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 the decrease in the price of oil and gas used to determine
    the Partnership's reserves for January 1, 1998 as compared to 1997.


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 $121,200  in
the six months ended June 30, 1998 as compared to approximately $335,600 in
the  six  months ended June 30, 1997.  The primary source of the 1998  cash
flow from operating activities was profitable operations.

Cash  flows used in investing activities were approximately $2,400  in  the
six  months ended June 30, 1998 as compared to approximately $5,600 in  the
six  months ended June 30, 1997.  The principle use of the 1998  cash  flow
from investing activities was the additions to oil and gas properties.

Cash flows used in financing activities were approximately $121,000 in  the
six months ended June 30, 1998 as compared to approximately $379,500 in the
six  months ended June 30, 1997.  The only use in financing activities  was
the distributions to partners.

Total distributions during the six months ended June 30, 1998 were $121,000
of  which  $108,900 was distributed to the limited partners and $12,100  to
the general partners.  The per unit distribution to limited partners during
the  six months ended June 30, 1998 was $17.44.  Total distributions during
the  six  months  ended June 30, 1997 were $379,500 of which  $341,550  was
distributed  to  the limited partners and $37,950 to the general  partners.
The  per unit distribution to limited partners during the six months  ended
June 30, 1997 was $54.68.

The  source  for  the  1998  distributions of $121,000  were  oil  and  gas
operations   of   approximately  $121,200.   The  source   for   the   1997
distributions  of  $379,500  was oil and gas  operations  of  approximately
$335,600,  partially offset by the net change in oil and gas properties  of
approximately $5,600, with the balance from available cash on hand  at  the
beginning of the period.

Since  inception of the Partnership, cumulative monthly cash  distributions
of  $2,857,318  have  been made to the partners.   As  of  June  30,  1998,
$2,588,594 or $414.44 per limited partner unit has been distributed to  the
limited partners, representing a 83% return of the capital contributed.

As  of  June 30, 1998, the Partnership had approximately $77,200 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.

Information Systems for the Year 2000

The  Managing  General Partner provides all data processing  needs  of  the
Partnership.   The Managing General Partner has reviewed and evaluated  its
information  systems  to determine if its systems accurately  process  data
referencing   the   year   2000.   Primarily  all   necessary   programming
modifications  to  correct year 2000 referencing in  the  Managing  General
Partners  internal accounting and operating systems have been made to-date.
However  the  Managing General Partner has not completed its evaluation  of
its vendors and suppliers systems to determine the effect, if any, the non-
compliance  of  such systems would have on the operation  of  the  Managing
General Partnership or the operations 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
               ended June 30, 1998.


                                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: August 15, 1998