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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, 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 0-20298

         SOUTHWEST ROYALTIES INSTITUTIONAL 1990-91 INCOME PROGRAM
         Southwest Royalties Institutional Income Fund X-C, L.P.
                  (Exact name of registrant as specified
                  in its limited partnership agreement)

Delaware                                    75-2374449
(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 17.

<PAGE>
                     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, 1998 which are found in the Registrant's  Form
10-K  Report  for  1998 filed with the Securities and Exchange  Commission.
The December 31, 1998 balance sheet included herein has been taken from the
Registrant's  1998 Form 10-K Report.  Operating results for the  three  and
six month periods ended June 30, 1999 are not necessarily indicative of the
results that may be expected for the full year.

<PAGE>
         Southwest Royalties Institutional Income Fund X-C, L.P.

                              Balance Sheets


                                                 June 30,      December 31,
                                                   1999            1998
                                                ---------      ------------
                                               (unaudited)

  Assets

Current assets:
 Cash and cash equivalents                   $      9,068           5,341
 Receivable from Managing General Partner          50,116          46,203
                                                ---------       ---------
    Total current assets                           59,184          51,544
                                                ---------       ---------
Oil and gas properties - using the
 full cost method of accounting                 2,221,781       2,240,424
  Less accumulated depreciation,
   depletion and amortization                   1,919,479       1,889,479
                                                ---------       ---------
    Net oil and gas properties                    302,302         350,945
                                                ---------       ---------
                                             $    361,486         402,489
                                                =========       =========
  Liabilities and Partners' Equity

Current liability - Distributions payable    $         16              16
                                                ---------       ---------
Partners' equity:
 General partners                                (27,748)        (26,648)
 Limited partners                                 389,218         429,121
                                                ---------       ---------
    Total partners' equity                        361,470         402,473
                                                ---------       ---------
                                             $    361,486         402,489
                                                =========       =========

<PAGE>
         Southwest Royalties Institutional Income Fund X-C, L.P.

                         Statements of Operations
                               (unaudited)


                                 Three Months Ended      Six Months Ended
                                       June 30,              June 30,
                                    1999      1998        1999      1998

  Revenues

Income from net profits
 interests                    $    21,225     22,618     11,175     50,233
Interest                               56        193        119        593
                                  -------    -------    -------    -------
                                   21,281     22,811     11,294     50,826
                                  -------    -------    -------    -------

  Expenses

General and administrative         11,094     12,236     22,297     29,213
Depreciation, depletion and
 amortization                      10,000     32,000     30,000     61,000
                                  -------    -------    -------    -------
                                   21,094     44,236     52,297     90,213
                                  -------    -------    -------    -------
Net income (loss)             $       187   (21,425)   (41,003)   (39,387)
                                  =======    =======    =======    =======
Net income (loss) allocated to:

 Managing General Partner     $       917        952      (990)      1,945
                                  =======    =======     ======    =======
 General Partner              $       102        106      (110)        216
                                  =======    =======    =======    =======
 Limited Partners             $     (832)   (22,483)   (39,903)   (41,548)
                                  =======    =======    =======    =======
  Per limited partner unit    $     (.14)     (3.76)     (6.67)     (6.94)
                                  =======    =======    =======    =======

<PAGE>
         Southwest Royalties Institutional Income Fund X-C, L.P.

                         Statements of Cash Flows
                               (unaudited)


                                                        Six Months Ended
                                                             June 30,
                                                          1999      1998

Cash flows from operating activities:

 Cash received from income from net profits
  interests                                         $     3,425     92,344
 Cash paid to suppliers                                (18,460)   (17,465)
 Interest received                                          119        593
                                                        -------    -------
  Net cash provided by (used by) operating activities   (14,916)    75,472
                                                        -------    -------
Cash flows from investing activities:

 Cash received from sale of oil and gas properties       18,643          -
                                                        -------    -------
Cash flows used in financing activities:

 Distributions to partners                                    -   (89,999)
                                                        -------    -------

Net increase (decrease) in cash and cash equivalents      3,727    (14,527)

 Beginning of period                                      5,341     20,066
                                                        -------    -------
 End of period                                      $     9,068      5,539
                                                        =======    =======

                                                               (continued)

<PAGE>
         Southwest Royalties Institutional Income Fund X-C, L.P.

                   Statements of Cash Flows, continued
                               (unaudited)


                                                        Six Months Ended
                                                             June 30,
                                                          1999      1998

Reconciliation of net loss to net cash provided by
 (used in) operating activities:

Net loss                                            $  (41,003)   (39,387)

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

  Depreciation, depletion and amortization               30,000     61,000
  (Increase) decrease in receivables                    (7,750)     42,111
  Increase in payables                                    3,837     11,748
                                                        -------    -------
Net cash provided by (used in) operating activities $  (14,916)     75,472
                                                        =======    =======

<PAGE>
         Southwest Royalties Institutional Income Fund X-C, L.P.
                     (a Delaware limited partnership)

                      Notes to Financial Statements


1.   Organization
     Southwest  Royalties Institutional 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 June 30, 1999, and  for  the
     three  and  six  months  ended June 30, 1999, 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, 1998.

<PAGE>

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

General

Southwest Royalties Institutional 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 Royalties Institutional  1990-
91  Income Program.  Minimum capital requirements for the Partnership  were
met on January 28, 1992, with the offering of limited partnership interests
concluding April 30, 1992, with 340 limited partners purchasing 5,983 units
for $2,991,500.

The Partnership was formed to acquire royalty and net profits 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 during 1999.

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, 1999, the net capitalized costs  did  not
exceed the estimated present value of oil and gas reserves.  The oil  price
environment experienced during 1998 had an adverse affect on the  Company's
revenues  and  operating cash flow.  Further declines of oil prices  during
1999  could  result in additional decreases in the carrying  value  of  the
Company's oil and gas properties.



<PAGE>
Results of Operations

A.  General Comparison of the Quarters Ended June 30, 1999 and 1998

The  following  table  provides certain information  regarding  performance
factors for the quarters ended June 30, 1999 and 1998:

                                               Three Months
                                                  Ended          Percentage
                                                 June 30,         Increase
                                              1999       1998    (Decrease)
                                              ----       ----    ----------

Average price per barrel of oil          $    14.79     10.86      36%
Average price per mcf of gas             $     1.97      2.03     (3%)
Oil production in barrels                     8,600    10,300    (17%)
Gas production in mcf                        15,370    15,200       1%
Income from net profits interests        $   21,225    22,618     (6%)
Partnership distributions                $        -    12,000   (100%)
Limited partner distributions            $        -    10,800   (100%)
Per unit distribution to limited
 partners                                $        -      1.81   (100%)
Number of limited partner units               5,983     5,983


Revenues

The  Partnership's income from net profits interests decreased  to  $21,225
from $22,618 for the quarters ended June 30, 1999 and 1998, respectively, a
decrease  of  6%.   The principal factors affecting the comparison  of  the
quarters ended June 30, 1999 and 1998 are as follows:

1.  The  average  price  for a barrel of oil received  by  the  Partnership
    increased  during the quarter ended June 30, 1999 as  compared  to  the
    quarter  ended June 30, 1998 by 36%, or $3.93 per barrel, resulting  in
    an  increase  of  approximately $40,500  in  income  from  net  profits
    interests.  Oil sales represented 81% of total oil and gas sales during
    the  quarters ended June 30, 1999 as compared to 78% during the quarter
    ended June 30, 1998.

    The  average  price  for  an  mcf of gas received  by  the  Partnership
    decreased during the same period by 3%, or $.06 per mcf, resulting in a
    decrease of approximately $900 in income from net profits interests.

    The  net total increase in income from net profits interests due to the
    change  in prices received from oil and gas production is approximately
    $39,600.   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.


<PAGE>
2.  Oil  production decreased approximately 1,700 barrels or 17% during the
    quarter  ended June 30, 1999 as compared to the quarter ended June  30,
    1998,  resulting in a decrease of approximately $25,100 in income  from
    net profits interests.

    Gas  production increased approximately 170 mcf or 1% during  the  same
    period,  resulting in a increase of approximately $300 in  income  from
    net profits interests.

    The  net total decrease in income from net profits interests due to the
    change  in  production is approximately $24,800.  The decrease  in  oil
    production is due primarily to downtime and natural decline.

3.  Lease  operating  costs  and  production  taxes  were  17%  lower,   or
    approximately $20,200 less during the quarter ended June  30,  1999  as
    compared  to  the  quarter ended June 30, 1998.  The decline  in  lease
    operating  costs  is primarily in relation to the drop  in  oil  prices
    experienced  throughout 1998 and into the first  six  months  of  1999,
    which  made it uneconomical to perform workovers necessary to  increase
    production and perform major repairs thus making it necessary to  shut-
    in some wells.

Costs and Expenses

Total costs and expenses decreased to $21,094 from $44,236 for the quarters
ended  June  30,  1999  and 1998, respectively, a  decrease  of  52%.   The
decrease  is  the  result  of  lower  depletion  expense  and  general  and
administrative expense.

1.  General and administrative costs consists of independent accounting and
    engineering  fees,  computer services, postage,  and  Managing  General
    Partner personnel costs.  General and administrative costs decreased 9%
    or  approximately  $1,100 during the quarter ended  June  30,  1999  as
    compared to the quarter ended June 30, 1998.

2.  Depletion expense decreased to $10,000 for the quarter ended  June  30,
    1999  from  $32,000  for the same period in 1998.   This  represents  a
    decrease  of 69%.  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  decline in depletion expense between the  comparative
    periods were the increase in the price of oil and gas used to determine
    the  Partnership's reserves for April 1, 1999 as compared to  1998  and
    the decrease in gross oil and gas revenues.

<PAGE>
B.  General  Comparison of the Six Month Periods Ended June  30,  1999  and
    1998

The  following  table  provides certain information  regarding  performance
factors for the six month periods ended June 30, 1999 and 1998:

                                                Six Months
                                                  Ended          Percentage
                                                 June 30,         Increase
                                              1999       1998    (Decrease)
                                              ----       ----    ----------

Average price per barrel of oil          $   12.38      11.75       5%
Average price per mcf of gas             $    1.82       1.79       2%
Oil production in barrels                   17,600     21,900    (20%)
Gas production in mcf                       28,500     33,900    (16%)
Income from net profits interests        $  11,175     50,233    (78%)
Partnership distributions                $       -     90,000   (100%)
Limited partner distributions            $       -     81,000   (100%)
Per unit distribution to limited
 partners                                $       -      13.54   (100%)
Number of limited partner units              5,983      5,983

Revenues

The  Partnership's income from net profits interests decreased  to  $11,175
from $50,233 for the six months ended June 30, 1999 and 1998, respectively,
a  decrease of 78%.  The principal factors affecting the comparison of  the
six months ended June 30, 1999 and 1998 are as follows:

1.  The  average  price  for a barrel of oil received  by  the  Partnership
    increased during the six months ended June 30, 1999 as compared to  the
    six months ended June 30, 1998 by 5%, or $.63 per barrel, resulting  in
    an  increase  of  approximately $13,800  in  income  from  net  profits
    interests.  Oil sales represented 81% of total oil and gas sales during
    the  six  months ended June 30, 1999 as compared to 81% during the  six
    months ended June 30, 1998.

    The  average  price  for  an  mcf of gas received  by  the  Partnership
    increased  during the same period by 2%, or $.03 per mcf, resulting  in
    an  increase  of  approximately  $1,000  in  income  from  net  profits
    interests.

    The  total  increase in income from net profits interests  due  to  the
    change  in prices received from oil and gas production is approximately
    $14,800.   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.

<PAGE>
2.  Oil  production decreased approximately 4,300 barrels or 20% during the
    six months ended June 30, 1999 as compared to the six months ended June
    30,  1998,  resulting in a decrease of approximately $53,200 in  income
    from net profits interests.

    Gas production decreased approximately 5,400 mcf or 16% during the same
    period, resulting in a decrease of approximately $9,800 in income  from
    net profits interests.

    The  total  decrease in income from net profits interests  due  to  the
    change in production is approximately $63,000.  The decrease in oil and
    gas  production  is due primarily to mechanical downtime  and  property
    sales.

3.  Lease   operating  costs  and  production  taxes  were  3%  lower,   or
    approximately $9,300 less during the six months ended June 30, 1999  as
    compared to the six months ended June 30, 1998.

Costs and Expenses

Total  costs  and expenses decreased to $52,297 from $90,213  for  the  six
months ended June 30, 1999 and 1998, respectively, a decrease of 42%.   The
decrease is the result of a decrease in general and administrative  expense
and depletion expense.

1.  General and administrative costs consists of independent accounting and
    engineering  fees,  computer services, postage,  and  Managing  General
    Partner  personnel costs.  General and administrative  costs  decreased
    24%  or approximately $6,900 during the six months ended June 30,  1999
    as  compared  to the six months ended June 30, 1998.  The  decrease  of
    general  and  administrative  costs were  in  part  due  to  additional
    accounting costs incurred in 1998 in relation to the outsourcing of K-1
    tax  package preparation; a change in auditors requiring opinions  from
    both  the  predecessors and successor auditors  and  a  new  accounting
    pronouncement requiring review by the independent auditors of  the  10-
    Q's.   The Managing General Partner has also made an effort to cut back
    on general and administrative costs whenever and wherever possible.

2.  Depletion  expense decreased to $30,000 for the six months  ended  June
    30,  1999 from $61,000 for the same period in 1998.  This represents  a
    decrease  of 51%.  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  decline in depletion expense between the  comparative
    periods were the increase in the price of oil and gas used to determine
    the  Partnership's reserves for April 1, 1999 as compared to  1998  and
    the decrease in gross oil and gas revenues.

<PAGE>
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 (used in) operating activities were  approximately
$(14,900)   in  the  six  months  ended  June  30,  1999  as  compared   to
approximately  $75,500 in the six months ended June 30, 1998.   Cash  flows
were used in oil and gas operations.

Cash  flows provided by investing activities were approximately $18,600  in
the six months ended June 30, 1999.  There were no investing activities  in
the  six months ended June 30, 1998.  The principle source of the 1999 cash
flow from investing activities was the sale of oil and gas properties.

There  were  no financing activities during the six months ended  June  30,
1999.  Cash flows used in financing activities in the six months ended June
30, 1998 were approximately $90,000.

There  were  no  distributions during the six months ended June  30,  1999.
Total  distributions during the six months ended June 30, 1998 were $90,000
of  which $81,000 was distributed to the limited partners and $9,000 to the
general partners.  The per unit distribution to limited partners during the
six months ended June 30, 1998 was $13.54.

The  sources  for  the  1998  distributions of $90,000  were  oil  and  gas
operations  of approximately $75,500, with the balance from available  cash
on hand at the beginning of the period.

Since  inception of the Partnership, cumulative monthly cash  distributions
of  $2,572,968  have  been made to the partners.   As  of  June  30,  1999,
$2,327,528 or $389.02 per limited partner unit has been distributed to  the
limited partners, representing a 78% return of the capital contributed.

As  of  June 30, 1999, the Partnership had approximately $59,200 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.

<PAGE>
Liquidity - Managing General Partner

The  Managing General Partner has a highly leveraged capital structure with
over   $21.0  million  of  interest  payments  due  in  1999  on  its  debt
obligations.   Due  to  severely depressed commodity prices,  the  Managing
General  Partner  is experiencing difficulty in generating sufficient  cash
flow  to  meet  its obligations and sustain its operations.   The  Managing
General  Partner is currently in the process of renegotiating the terms  of
its  various obligations with its creditors and/or attempting to  seek  new
lenders  or  equity investors.  Additionally, the Managing General  Partner
would   consider  disposing  of  certain  assets  in  order  to  meet   its
obligations.

There  can  be  no  assurance  that  the Managing  General  Partner's  debt
restructuring efforts will be successful or that the lenders will agree  to
a   course   of  action  consistent  with  the  Managing  General  Partners
requirements  in restructuring the obligations.  Even if such agreement  is
reached,  it  may  require approval of additional  lenders,  which  is  not
assured.   Furthermore, there can be no assurance that the sales of  assets
can  be  successfully  accomplished on terms  acceptable  to  the  Managing
General   Partner.   Under  current  circumstances,  the  Managing  General
Partner's  ability to continue as a going concern depends upon its  ability
to  (1)  successfully  restructure  its obligations  or  obtain  additional
financing  as  may  be  required, (2) maintain  compliance  with  all  debt
covenants, (3) generate sufficient cash flow to meet its obligations  on  a
timely  basis, and (4) achieve satisfactory levels of future earnings.   If
the  Managing  General Partner is unsuccessful in its efforts,  it  may  be
unable to meet its obligations making it necessary to undertake such  other
actions as may be appropriate to preserve asset values.

Information Systems for the Year 2000

The  Managing  General Partner provides all data processing  needs  of  the
Partnership.  The Managing General Partner is continuing in its  effort  to
identify  and  assess its exposure to the potential Year 2000 software  and
imbedded  chip processing and date sensitivity issue.  Through the Managing
General  Partners  data processing subsidiary, Midland Southwest  Software,
Inc., the Managing General Partner proactively initiated a plan to identify
applicable hardware and software, assess impact and effect, estimate costs,
construct and implement corrective actions, and prepare contingency plans.

Identification & Assessment

The  Managing  General  Partner currently believes it  has  identified  the
internal  and external software and hardware that may have date sensitivity
problems.  Four critical systems and/or functions were identified:  (1) the
proprietary software of the Partnership (OGAS) that is used for oil  &  gas
property management and financial accounting functions, (2) the DEC VAX/VMS
hardware and operating system, (3) various third-party application software
including  lease  economic  analysis, fixed  asset  management,  geological
applications, and payroll/human resource programs, and (4) External Agents.

The  proprietary  software of the Partnership is currently  in  process  of
meeting  compliance requirements with an estimated completion date of  mid-
year  1999.   Since this is an internally generated software  package,  the
Managing General Partner has estimated the cost to be approximately $25,000
by  estimating the necessary man-hours.  These modifications are being made
by internal staff and do not represent additional costs to the Partnership.
The  Managing General Partner has not made contingency plans at  this  time
since  the  conversion is ahead of schedule and being handled  by  Managing
General  Partner controlled internal programmers.  Given the complexity  of
the systems being modified, it is anticipated that some problems may arise,
but  with  an expected early completion date, the Managing General  Partner
feels that adequate time is available to overcome unforeseen delays.

DEC has released a fully compliant version of its operating system that  is
used  by  the  Partnership on the DEC VAX system.  It will be installed  in
August 1999, the Managing General Partner believes that this will solve any
potential problems on the system.

<PAGE>

The  Managing  General Partner has identified various third-party  software
that may have date sensitivity problems and is working with the vendors  to
secure  solutions as well as prepare contingency plans.  After  review  and
evaluation  of  the vendor plans and status, the Managing  General  Partner
believes that the problems will be resolved prior to the year 2000  or  the
alternate  contingency plan will sufficiently and adequately remediate  the
problem so that there is no material disruption to business functions.

The  External  Agents  of  the  Partnership include  suppliers,  customers,
owners,  vendors, banks, product purchasers including pipelines, and  other
oil  and  gas property operators.  The Managing General Partner is  in  the
process of identifying and communicating with each critical External  Agent
about  its  plan  and progress thereof in addressing the Year  2000  issue.
This process is on schedule and the Managing General Partner, at this time,
believes  that  there  should  be no material  interference  or  disruption
associated with any of the critical External Agent's functions necessary to
the   Partnership's  business.   The  Managing  General  Partner  estimates
completion of this audit by mid-year 1999 and believes that alternate plans
can  be  devised to circumvent any material problems arising from  critical
External Agent noncompliance.

Cost

To  date,  the Managing General Partner has incurred only minimal  internal
man-hour costs for identification, planning, and maintenance.  The Managing
General  Partner believes that the necessary additional costs will also  be
minimal  and most will fall under normal and general maintenance procedures
and updates.  An accurate cost cannot be determined at this time, but it is
expected  that  the total cost to remediate all systems  to  be  less  than
$50,000.

Risks/Contingency

The  failure to correct critical systems of the Partnership, or the failure
of  a  material business partner or External Agent to resolve critical Year
2000  issues  could  have a serious adverse impact on the  ability  of  the
Partnership  to  continue operations and meet obligations.   Based  on  the
Managing  General  Partner's  evaluation and  assessment  to  date,  it  is
believed  that any interruption in operation will be minor and  short-lived
and  pose no material monetary loss, safety, or environmental risk  to  the
Partnership.   However, until all assessment is complete, it is  impossible
to accurately identify the risks, quantify potential impacts or establish a
final  contingency  plan. The Managing General Partner  believes  that  its
assessment and contingency planning will be complete no later than mid-year
1999.

Worst Case Scenario

The  Securities and Exchange Commission requires that public companies must
forecast the most reasonably likely worst case Year 2000 scenario, assuming
that  the  Managing  General Partner's Year 2000  plan  is  not  effective.
Analysis  of the most reasonably likely worst case Year 2000 scenarios  the
Partnership  may face leads to contemplation of the following possibilities
which,  though  considered  highly  unlikely,  must  be  included  in   any
consideration  of worst cases: widespread failure of electrical,  gas,  and
similar   supplies   by  utilities  serving  the  Partnership;   widespread
disruption  of  the  services of communications  common  carriers;  similar
disruption to means and modes of transportation for the Partnership and its
employees, contractors, suppliers, and customers; significant disruption to
the  Partnership's  ability to gain access to,  and  continue  working  in,
office  buildings  and other facilities; and the failure, of  third-parties
systems,  the  effects  of which would have a cumulative  material  adverse
impact  on  the  Partnership's  critical systems.   The  Partnership  could
experience  an inability by customers, traders, and others  to  pay,  on  a
timely  basis or at all, obligations owed to the Partnership.  Under  these
circumstances, the adverse effect on the Partnership, and the diminution of
Partnership revenues, could be material, although not quantifiable at  this
time.



<PAGE>
                       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, 1999.

<PAGE>
                                SIGNATURES


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

                                 SOUTHWEST ROYALTIES INSTITUTIONAL
                                 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, 1999

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