Page 18 of 18
                                 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 September 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 18.

<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 note 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
nine  month periods ended September 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

                                              September 30,   December 31,
                                                   1999           1998
                                              -------------   ------------
                                               (unaudited)
Assets

Current assets
 Cash and cash equivalents                     $   17,648          5,341
 Receivable from Managing General Partner          80,234         46,203
                                                ---------      ---------
     Total current assets                          97,882         51,544
                                                ---------      ---------
Oil and gas properties - using the
 full cost method of accounting                 2,221,662      2,240,424
  Less accumulated depreciation,
   depletion and amortization                   1,919,479      1,889,479
                                                ---------      ---------
     Net oil and gas properties                   302,183        350,945
                                                ---------      ---------
                                               $  400,065        402,489
                                                =========      =========

Liabilities and Partners' Equity

Current liability - Distribution payable       $        2             16
                                                ---------      ---------

Partners' equity
 General partners                                (22,261)       (26,648)
 Limited partners                                 422,324        429,121
                                                ---------      ---------
     Total partners' equity                       400,063        402,473
                                                ---------      ---------
                                               $  400,065        402,489
                                                =========      =========
<PAGE>

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

                         Statements of Operations
                                (unaudited)


                                Three Months Ended    Nine Months Ended
                                  September 30,         September 30,
                                  1999      1998        1999      1998
                                  ----      ----        ----      ----
Revenues

Income (loss) from net
 profits interests           $    72,607  (11,442)      83,782    38,792
Interest                             197       124         317       717
                                  ------   -------     -------   -------
                                  72,804  (11,318)      84,099    39,509
                                  ------   -------     -------   -------
Expenses

General and administrative         9,935    11,605      32,232    40,818
Depreciation, depletion and
 amortization                          -    12,000      30,000    73,000
                                  ------   -------     -------   -------
                                   9,935    23,605      62,232   113,818
                                  ------   -------     -------   -------
Net income (loss)            $    62,869  (34,923)      21,867  (74,309)
                                  ======   =======     =======   =======



Net income (loss) allocated to:

 Managing General Partner    $     5,658   (2,063)       4,668     (118)
                                  ======   =======     =======   =======
 General Partner             $       629     (229)         519      (13)
                                  ======   =======     =======   =======
 Limited Partners            $    56,582  (32,631)      16,680  (74,178)
                                  ======   =======     =======   =======
  Per limited partner unit   $      9.46    (5.45)        2.79    (12.40)
                                  ======   =======     =======   =======

<PAGE>

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

                         Statements of Cash Flows
                                (unaudited)


                                                      Nine Months Ended
                                                        September 30,
                                                       1999       1998
                                                       ----       ----
Cash flows from operating activities

 Cash received from income from net
  profits interests                                $   42,441    106,557
 Cash paid to suppliers                              (24,922)   (23,198)
 Interest received                                        317        717
                                                      -------    -------
  Net cash provided by operating activities            17,836     84,076
                                                      -------    -------
Cash flow from investing activities

 Cash received from sale of oil and gas
  Properties                                           18,762          -
                                                      -------    -------
Cash flows used in financing activities

 Distributions to partners                           (24,291)   (98,978)
                                                      -------    -------

Net increase (decrease) in cash and cash equivalents              12,307
(14,902)

 Beginning of period                                    5,341     20,066
                                                      -------    -------
 End of period                                     $   17,648      5,164
                                                      =======    =======

                                                             (continued)
<PAGE>

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

                    Statements of Cash Flows, continued
                                (unaudited)


                                                      Nine Months Ended
                                                        September 30,
                                                       1999       1998
                                                       ----       ----
Reconciliation of net income (loss) to net
 cash provided by operating activities

Net income (loss)                                  $   21,867   (74,309)

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

 Depreciation, depletion and amortization              30,000     73,000
 (Increase) decrease in receivables                  (41,341)     67,765
 Increase in payables                                   7,310     17,620
                                                      -------    -------
Net cash provided by operating activities          $   17,836     84,076
                                                      =======    =======


<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 September 30, 1999,  and  for
     the  three  and  nine months ended September 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 the third quarter of 1999.  The Partnership could possibly
experience a normal decline in 2000.

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 September 30, 1999, the net capitalized costs  did
not  exceed the estimated present value of oil and gas reserves.  A  return
to  the oil price environment experienced during the first two quarters  of
1999  would 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.

<PAGE>
Results of Operations

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

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

                                                 Three Months
                                                    Ended        Percentage
                                                September 30,     Increase
                                                1999      1998   (Decrease)
                                                ----      ----   ---------
Average price per barrel of oil            $   18.77     10.42      80%
Average price per mcf of gas               $    2.01      1.44      40%
Oil production in barrels                      8,740     9,400     (7%)
Gas production in mcf                         12,860    14,700    (13%)
Income (loss) from net profits interests   $  72,607  (11,422)     736%
Partnership distributions                  $  16,277     9,000      81%
Limited partner distributions              $  16,277     8,100     101%
Per unit distribution to limited partners  $    2.72      1.35     101%
Number of limited partner units                5,983     5,983

Revenues

The  Partnership's income from net profits interests increased  to  $72,607
from  $(11,442)  for  the  quarters ended  September  30,  1999  and  1998,
respectively,  an  increase of 736%.  The principal factors  affecting  the
comparison  of  the  quarters ended September 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 September 30, 1999 as compared  to
     the  quarter  ended  September 30, 1998 by 80%, or $8.35  per  barrel,
     resulting in an increase of approximately $78,500 in income  from  net
     profits  interests.  Oil sales represented 86% of total  oil  and  gas
     sales  during the quarter ended September 30, 1999 as compared to  82%
     during the quarter ended September 30, 1998.

     The  average  price  for  an mcf of gas received  by  the  Partnership
     increased during the same period by 40%, or $.57 per mcf, resulting in
     an  increase  of  approximately $8,400  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
     $86,900.  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 660 barrels or  7%  during  the
   quarter  ended  September  30, 1999 as compared  to  the  quarter  ended
   September 30, 1998, resulting in a decrease of approximately $12,400  in
   income from net profits interests.

    Gas production decreased approximately 1,840 mcf or 13% during the same
    period, resulting in a decrease of approximately $3,700 in income  from
    net profits interests.

    The  total  decrease in income from net profits interests  due  to  the
    change in production is approximately $16,100.

3.  Lease  operating  costs  and  production  taxes  were  10%  lower,   or
    approximately $13,200 less during the quarter ended September 30,  1999
    as compared to the quarter ended September 30, 1998.

Costs and Expenses

Total  costs and expenses decreased to $9,935 from $23,605 for the quarters
ended  September 30, 1999 and 1998, respectively, a decrease of  58%.   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
    14% or approximately $1,700 during the quarter ended September 30, 1999
    as compared to the quarter ended September 30, 1998.

2.  There was no depletion expense recorded for the quarter ended September
    30,  1999.  Depletion expense was recorded in the amount of $12,000 for
    the  same  period  in  1998.   This  represents  a  decrease  of  100%.
    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 October 1, 1999 as compared to 1998.

<PAGE>

B.   General Comparison of the Nine Month Periods Ended September 30,  1999
and 1998

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

                                                 Nine Months
                                                    Ended        Percentage
                                                September 30,     Increase
                                                1999      1998   (Decrease)
                                                ----      ----   ---------
Average price per barrel of oil            $   14.50     11.35     28%
Average price per mcf of gas               $    2.02      1.68     20%
Oil production in barrels                     26,340    31,300   (16%)
Gas production in mcf                         38,410    48,600   (21%)
Income from net profits interests          $  83,782    38,792    116%
Partnership distributions                  $  24,277    99,000   (75%)
Limited partner distributions              $  23,477    89,100   (74%)
Per unit distribution to limited partners  $    3.92     14.89   (74%)
Number of limited partner units                5,983     5,983

Revenues

The  Partnership's income from net profits interests increased  to  $83,782
from  $38,792  for  the  nine months ended September  30,  1999  and  1998,
respectively,  an  increase of 116%.  The principal factors  affecting  the
comparison  of  the nine months ended September 30, 1999 and  1998  are  as
follows:

1.  The  average  price  for a barrel of oil received  by  the  Partnership
    increased  during the nine months ended September 30, 1999 as  compared
    to  the  nine  months ended September 30, 1998 by  28%,  or  $3.15  per
    barrel,  resulting  in an increase of approximately $98,600  in  income
    from net profits interests.  Oil sales represented 83% of total oil and
    gas  sales during the nine months ended September 30, 1999 as  compared
    to 81% during the nine months ended September 30, 1998.

    The  average  price  for  an  mcf of gas received  by  the  Partnership
    increased during the same period by 20%, or $.34 per mcf, resulting  in
    an  increase  of  approximately $16,500  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
    $115,100.  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 4,960 barrels or 16% during the
    nine  months  ended September 30, 1999 as compared to the  nine  months
    ended  September  30,  1998, resulting in a decrease  of  approximately
    $71,900 in income from net profits interests.

    Gas  production  decreased approximately 10,190 mcf or 21%  during  the
    same period, resulting in a decrease of approximately $20,600 in income
    from net profits interests.

    The  total  decrease in income from net profits interests  due  to  the
    change  in  production  is  approximately  $92,500.   The  decrease  in
    production was due in part to property sales and downtime.

3.  Lease   operating  costs  and  production  taxes  were  6%  lower,   or
    approximately  $22,500 less during the nine months ended September  30,
    1999 as compared to the nine months ended September 30, 1998.

Costs and Expenses

Total  costs and expenses decreased to $62,232 from $113,818 for  the  nine
months ended September 30, 1999 and 1998, respectively, a decrease of  45%.
The  decrease is the result of lower 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
    21%  or approximately $8,600 during the nine months ended September 30,
    1999  as  compared to the nine months ended September  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  nine  months  ended
    September  30,  1999 from $73,000 for the same period  in  1998.   This
    represents a decrease of 59%.  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 October 1, 1999 as compared
    to 1998.

<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 operating activities were approximately $17,800  in
the  nine  months  ended  September 30, 1999 as compared  to  approximately
$84,100 in the nine months ended September 30, 1998.  The primary source of
the 1999 cash flow from operating activities was profitable operations.

Cash  flows provided by investing activities were approximately $18,800  in
the  nine  months  ended  September 30, 1999.  There  were  no  cash  flows
provided  by  investing activities in the nine months ended  September  30,
1998.

Cash  flows used in financing activities were approximately $24,300 in  the
nine  months ended September 30, 1999 as compared to approximately  $98,900
in  the  nine  months ended September 30, 1998.  The only use in  financing
activities was the distributions to partners.

Total  distributions during the nine months ended September 30,  1999  were
$24,277  of which $23,477 was distributed to the limited partners and  $800
to  the  general  partners.  The per unit distribution to limited  partners
during  the  nine  months  ended  September  30,  1999  was  $3.92.   Total
distributions during the nine months ended September 30, 1998 were  $99,000
of  which $89,100 was distributed to the limited partners and $9,900 to the
general partners.  The per unit distribution to limited partners during the
nine months ended September 30, 1998 was $14.89.

The source for the 1999 distributions of $24,277 was oil and gas operations
of  approximately  $17,800  and  a  change  in  oil  and  gas  property  of
approximately $18,800, resulting in excess for contingencies or  subsequent
distributions.  The sources for the 1998 distributions of $99,000 were  oil
and  gas  operations  of  approximately  $84,100,  with  the  balance  from
available cash on hand at the beginning o the period.

Since  inception of the Partnership, cumulative monthly cash  distributions
of  $2,597,245 have been made to the partners.  As of September  30,  1999,
$2,351,005 or $392.95 per limited partner unit has been distributed to  the
limited partners, representing a 79% return of the capital contributed.

As  of  September  30, 1999, the Partnership had approximately  $97,900  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 within next twelve  months  on
its  debt  obligations.   Due  to the severely depressed  commodity  prices
experienced for the past eighteen months, 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 has identified and assessed  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  an  internal  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 identified the internal
and  external  software  and  hardware that  had  the  potential  for  date
sensitivity   problems.   Four  critical  systems  and/or  functions   were
identified  and addressed:  (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   has   met   compliance
requirements.  Since this is an internally generated software package,  the
Managing  General  Partner  incurred approximately  $25,000  in  man-hours.
Modifications were made by internal staff and did 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 that were modified, it is
anticipated  that  some  problems  may arise,  but  having  met  the  early
completion  date,  the Managing General Partner feels  that  adequate  time
remains available to overcome unforeseen delays.




<PAGE>
DEC has released a fully compliant version of its operating system that  is
used  by  the  Partnership on the DEC VAX system.  It  was  installed,  the
Managing  General Partner believes that this solved any potential  problems
on the system.

The  Managing  General Partner has identified various third-party  software
that may have date sensitivity problems and is continuing to work 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 year end 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,  due  to  the  external  nature  of  the  potential
problems,  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 year-end 1999.

<PAGE>
Worst Case Scenario
The  Securities  and  Exchange  Commission  requires  public  companies  to
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) No reports on Form 8-K were filed during the quarter for
             which this report is filed.


<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:     November 15, 1999

<PAGE>