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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 September 30, 2003

                                    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 0-19601

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

Delaware                                          75-2332174
(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)

                      ________(432) 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 _____

Indicate  by  check  mark whether registrant is an  accelerated  filer  (as
defined in Rule 12b-2 of the Exchange Act).

                             Yes ____ No __X__


         The total number of pages contained in this report is 24.



Glossary of Oil and Gas Terms
The  following are abbreviations and definitions of terms commonly used  in
the  oil  and  gas industry that are used in this filing.  All  volumes  of
natural gas referred to herein are stated at the legal pressure base to the
state  or area where the reserves exit and at 60 degrees Fahrenheit and  in
most instances are rounded to the nearest major multiple.

     Bbl. One stock tank barrel, or 42 United States gallons liquid volume.

     Developmental well. A well drilled within the proved area of an oil or
natural gas reservoir to the depth of a stratigraphic horizon known  to  be
productive.

     Exploratory well. A well drilled to find and produce oil or gas in  an
unproved  area to find a new reservoir in a field previously  found  to  be
productive of oil or natural gas in another reservoir or to extend a  known
reservoir.

     Farm-out  arrangement. An agreement whereby the owner of the leasehold
or  working  interest  agrees to assign his interest  in  certain  specific
acreage  to  the assignee, retaining some interest, such as  an  overriding
royalty interest, subject to the drilling of one (1) or more wells or other
performance by the assignee.

     Field. An area consisting of a single reservoir or multiple reservoirs
all  grouped  on  or  related to the same individual geological  structural
feature and/or stratigraphic condition.

     Mcf. One thousand cubic feet.

     Net  Profits  Interest.  An agreement whereby  the  owner  receives  a
specified  percentage of the defined net profits from a producing  property
in  exchange for consideration paid.  The net profits interest  owner  will
not otherwise participate in additional costs and expenses of the property.

     Oil. Crude oil, condensate and natural gas liquids.

     Overriding  royalty  interest. Interests that  are  carved  out  of  a
working  interest, and their duration is limited by the term of  the  lease
under which they are created.


     Present  value  and  PV-10 Value. When used with respect  to  oil  and
natural gas reserves, the estimated future net revenue to be generated from
the  production of proved reserves, determined in all material respects  in
accordance  with  the  rules and regulations of the  SEC  (generally  using
prices  and costs in effect as of the date indicated) without giving effect
to  non-property  related  expenses  such  as  general  and  administrative
expenses,  debt service and future income tax expenses or to  depreciation,
depletion  and  amortization, discounted using an annual discount  rate  of
10%.

     Production  costs.  Costs incurred to operate and maintain  wells  and
related  equipment  and facilities, including depreciation  and  applicable
operating  costs  of support equipment and facilities and  other  costs  of
operating and maintaining those wells and related equipment and facilities.

     Proved Area. The part of a property to which proved reserves have been
specifically attributed.

     Proved  developed oil and gas reserves. Proved developed oil  and  gas
reserves  are  reserves that can be expected to be recovered from  existing
wells with existing equipment and operating methods.

     Proved properties. Properties with proved reserves.

     Proved  reserves. The estimated quantities of crude oil, natural  gas,
and  natural  gas liquids that geological and engineering data  demonstrate
with  reasonable  certainty to be recoverable in future  years  from  known
reservoirs under existing economic and operating conditions.

     Proved  undeveloped reserves. Proved undeveloped oil and gas  reserves
are  reserves that are expected to be recovered from new wells on undrilled
acreage,  or  from existing wells where a relatively major  expenditure  is
required for recompletion.

     Reservoir.  A porous and permeable underground formation containing  a
natural  accumulation  of  producible  oil  or  gas  that  is  confined  by
impermeable  rock  or water barriers and is individual  and  separate  from
other reservoirs.

     Royalty  interest.  An  interest in an oil and  natural  gas  property
entitling  the  owner to a share of oil or natural gas production  free  of
costs of production.

     Working  interest.  The operating interest that gives  the  owner  the
right  to  drill, produce and conduct operating activities on the  property
and a share of production.

     Workover.  Operations  on  a producing well  to  restore  or  increase
production.




                      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, 2002, which are found  in  the  Registrant's
Amendment No. 1 to its Annual Report on Form 10-K for 2002 filed  with  the
Securities and Exchange Commission on November 12, 2003.  The December  31,
2002  balance  sheet included herein has been derived from the Registrant's
Amendment  No.  1  to its Annual Report on Form 10-K for  2002.   Operating
results  for the three and nine month periods ended September 30, 2003  are
not necessarily indicative of the results for the full year.

Introductory Note - Statement of Financial Accounting Standard No. 143
The  Partnership implemented SFAS No. 143 effective January  1,  2003  (See
Note 3) to the Partnership's financial statements.

Introductory Note - Depletion Method
During  the fourth quarter of 2002, the Partnership changed its  method  of
providing  for depletion from the units-of-revenue method to the  units-of-
production  method  as  described in Notes 4 and  5  to  the  Partnership's
financial statements.

This  change  in depletion method was applied as a cumulative effect  of  a
change  in  accounting  principle effective as of  January  1,  2002.   The
unaudited condensed financial statements of the Partnership for the periods
ended September 30, 2002, included herein, have been restated (as described
in  Notes 4 and 5 to the Partnership's financial statements) using the  new
depletion   method  and  differ  from  those  previously  issued   in   the
Partnership's Quarterly Report on Form 10-Q for the periods ended September
30, 2002.



          Southwest Royalties Institutional Income Fund X-B, L.P.
                              Balance Sheets

                                 Septembe  December
                                  r 30,      31,
                                   2003      2002
                                  -----     -----
                                 (unaudit
                                   ed)
Assets
- ---------

Current assets:
 Cash and cash equivalents    $  41,766    64,725
  Receivable  from  Managing     74,506    78,656
General Partner
                                 --------  --------
                                 -----     -----
   Total current assets          116,272   143,381
                                 --------  --------
                                 -----     -----
Oil  and  gas  properties  -
using the full-
 cost method of accounting       3,931,84  3,851,38
                                 1         2
       Less      accumulated
depreciation,
         depletion       and     3,591,25  3,591,85
amortization                     7         3
                                 --------  --------
                                 -----     -----
      Net   oil   and    gas     340,584   259,529
properties
                                 --------  --------
                                 -----     -----
                              $  456,856   402,910
                                 =======   =======

Liabilities  and   Partners'
Equity
- ----------------------------
- ---------

Current     liability      -  $  332       -
distribution payable
                                 --------  --------
                                 -----     -----
Other long term liabilities      202,000   -
                                 --------  --------
                                 -----     -----
Partners' equity:
 General partners                (54,569)  (41,530)
 Limited partners                309,093   444,440
                                 --------  --------
                                 -----     -----
   Total partners' equity        254,524   402,910
                                 --------  --------
                                 -----     -----
                              $  456,856   402,910
                                 =======   =======



          Southwest Royalties Institutional Income Fund X-B, L.P.
                         Statements of Operations
                                (unaudited)

                                    Three Months Ended   Nine Months Ended
                                      September 30,        September 30,
                                     2003       2002      2003      2002
                                             (Restated            (Restate
                                                 )                   d)
                                     ----       ----      ----      ----
Revenues
- ------------
Income from net profits          $ 29,906    86,970     209,809   176,030
interests
Interest                           57        188        322       427
Miscellaneous settlement           -         3,660      117       3,660
                                   --------  ---------  --------  --------
                                   -                    -         --
                                   29,963    90,818     210,248   180,117
                                   --------  ---------  --------  --------
                                   -                    -         --
Expenses
- ------------
General and administrative         21,523    20,260     67,688    58,748
Depreciation, depletion and        6,000     7,000      18,000    21,000
amortization
Accretion of asset retirement      3,811     -          11,522    -
obligation
                                   --------  ---------  --------  --------
                                   -                    -         --
                                   31,334    27,260     97,210    79,748
                                   --------  ---------  --------  --------
                                   -                    -         --
Net income (loss) before           (1,371)   63,558     113,038   100,369
cumulative effects

Cumulative effect of change in
accounting
  principle - SFAS No. 143 -       -         -          (91,424)  -
See Note 3
Cumulative effect of change in
accounting principle
  - change in depletion method     -         -          -         (55,000)
- - See Note 4
                                   --------  ---------  --------  --------
                                   -                    -         --
Net income (loss)                $ (1,371)   63,558     21,614    45,369
                                   =====     =====      =====     ======
Net income (loss) allocated to:

  Managing General Partner       $ 417       6,350      3,565     10,923
                                   =====     =====      =====     ======
  General Partner                $ 46        706        396       1,214
                                   =====     =====      =====     ======
  Limited Partners               $ (1,834)   56,502     17,653    33,232
                                   =====     =====      =====     ======
     Per limited partner unit    $  (.16)         5.05
before cumulative effect                                8.94      7.89
     Cumulative effects per        -         -           (7.36)
limited partner unit                                              (4.92)
                                   --------  ---------  --------  --------
                                   -                    -         --
     Per limited partner unit    $  (.16)         5.05
                                                        1.58      2.97
                                   =====     =====      =====     ======
Pro forma amounts assuming
change is applied
  retroactively (See Note 3):
  Net income before cumulative   $ -         60,011     -         89,728
effect
                                   =====     =====      =====     ======
    Per  limited  partner  unit  $ -           4.77     -           7.03
(11,181.0)
                                   =====     =====      =====     ======
  Net income                     $ -         60,011     -         34,728
                                   =====     =====      =====     ======
    Per  limited  partner  unit  $ -           4.77     -           2.11
(11,181.0)
                                   =====     =====      =====     ======


          Southwest Royalties Institutional Income Fund X-B, L.P.
                         Statements of Cash Flows
                                (unaudited)

                                                     Nine Months Ended
                                                       September 30,
                                                       2003     2002
                                                              (Restate
                                                                 d)
                                                       ----     ----
            Cash flows from operating activities

            Cash received from income from net
              profits interests                    $ 198,044  154,014
            Cash paid to suppliers                   (51,774  (56,135)
                                                     )
            Interest received                        322      427
            Miscellaneous settlement                 117      3,660
                                                     -------  --------
                                                     ---      --
              Net cash provided by operating         146,709  101,966
            activities
                                                     -------  --------
                                                     ---      --
            Cash flows used in financing
            activities

            Distributions to partners                (169,66  (100,012
                                                     8)       )
                                                     -------  --------
                                                     ---      --
              Net decrease in cash and cash          (22,959  (1,954)
            equivalents                              )

            Beginning of period                      64,725   48,952
                                                     -------  --------
                                                     ---      --
            End of period                          $ 41,766   50,906
                                                     ======   ======
            Reconciliation of net income to net
            cash
            provided by operating activities

            Net income                             $ 21,614   45,369

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

            Depreciation, depletion and              18,000   21,000
            amortization
            Accretion of asset retirement            11,522   -
            obligation
            Cumulative effect of change in
            accounting
              principle - SFAS No. 143               91,424   -
            Cumulative effect of change in
            accounting
              principle - change in depletion        -        55,000
            method
            Increase in receivables                  (11,765  (22,016)
                                                     )
            Increase in payables                     15,914   2,613
                                                     -------  --------
                                                     ---      --
            Net cash provided by operating         $ 146,709  101,966
            activities
                                                     ======   ======
            Noncash investing and financing
            activities:

            Increase in oil and gas properties -
            Adoption
              of SFAS No. 143                      $ 101,341  -
                                                     ======   ======
            Decrease in oil and gas properties -
            SFAS No. 143
              Asset retirement obligation          $ 2,287    -
            settlement
                                                     ======   ======


         Southwest Royalties Institutional Income Fund X-B, L.P.
                     (a Delaware limited partnership)

                      Notes to Financial Statements

1.   Organization
     Southwest  Royalties Institutional Income Fund X-B, L.P. was organized
     under  the laws of the state of Delaware on November 27, 1990 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 a variety of 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  100%      -
capital contributions
Oil and gas sales        90%       10%
All other revenues       90%       10%
Organization        and  100%      -
offering costs (1)
Amortization         of  100%      -
organization costs
Property    acquisition  100%      -
costs
Gain/loss  on  property  90%       10%
disposition
Operating           and  90%       10%
administrative    costs
(2)
Depreciation, depletion
and amortization
   of   oil   and   gas  100%      -
properties
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, 2003,  and  for
     the  three  and  nine months ended September 30, 2003,  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  Partnership's
     Amendment  No. 1 to its Annual Report on Form 10-K for the year  ended
     December 31, 2002, filed with SEC on November 12, 2003.

3.   Cumulative effect of change in accounting principle - SFAS No. 143
     On  January  1, 2003, the Partnership adopted Statement  of  Financial
     Accounting   Standards  No.  143,  Accounting  for  Asset   Retirement
     Obligations  ("SFAS No. 143").  Adoption of SFAS No. 143  is  required
     for  all  companies with fiscal years beginning after June  15,  2002.
     The new standard requires the Partnership to recognize a liability for
     the  present  value  of  all  legal obligations  associated  with  the
     retirement  of tangible long-lived assets and to capitalize  an  equal
     amount as a cost of the asset and depreciate the additional cost  over
     the  estimated  useful  life of the asset.  On January  1,  2003,  the
     Partnership    recorded   additional   costs,   net   of   accumulated
     depreciation,  of  approximately $101,341, a long  term  liability  of
     approximately  $192,765 and a loss of approximately  $91,424  for  the
     cumulative  effect  on  depreciation  of  the  additional  costs   and
     accretion  expense  on  the liability related to expected  abandonment
     costs  of  its oil and natural gas producing properties.  At September
     30,  2003,  the  asset  retirement obligation was  $202,000,  and  the
     increase  in  the balance from January 1, 2003 of $11,522  is  due  to
     accretion expense, partially offset by the plug and abandonment of oil
     and gas properties, which decreased the asset retirement obligation by
     $2,287.   The  pro forma amounts for the three and nine  months  ended
     September  30, 2002, which are presented on the face of the statements
     of  operations, reflect the effect of retroactive application of  SFAS
     No. 143.


          Southwest Royalties Institutional Income Fund X-B, L.P.
                     (a Delaware limited partnership)

                      Notes to Financial Statements

4.    Cumulative  effect  of change in accounting  principle  -  change  in
depletion method
     In  the  fourth  quarter of 2002, the Partnership changed  methods  of
     accounting  for  depletion  of capitalized costs  from  the  units-of-
     revenue  method to the units-of-production method.  The newly  adopted
     accounting  principle is preferable in the circumstances  because  the
     units-of-production method results in a better matching of  the  costs
     of  oil  and  gas production against the related revenue  received  in
     periods of volatile prices for production as have been experienced  in
     recent  periods.  Additionally, the units-of-production method is  the
     predominant  method used by full cost companies in  the  oil  and  gas
     industry,  accordingly, the change improves the comparability  of  the
     Partnership's   financial  statements  with  its  peer   group.    The
     Partnership   adopted  the  units-of-production  method  through   the
     recording  of a cumulative effect of a change in accounting  principle
     in  the  amount  of  $55,000 effective as of  January  1,  2002.   The
     Partnership's depletion for the three and nine months ended  September
     30,  2003  and  2002 has been calculated using the units-of-production
     method.  There was no effect due to the change in depletion method  on
     the quarter ended September 30, 2002.  The effect of the change on the
     nine  months  ended September 30, 2003 was to decrease net  income  by
     $55,000 ($4.92 per limited partner unit).

5.   September 30, 2002 Restatement
     During  the fourth quarter of 2002, the Partnership changed its method
     of  providing  for depletion from the units-of-revenue method  to  the
     units-of-production method as described in Note 4.

     This  change in the method used to implement the Partnership's  change
     in  the manner in which it determines depletion resulted in a decrease
     in the Partnership's previously reported net oil and gas properties of
     $53,000 from $312,529 to $259,529 as of December 31, 2002 and did  not
     effect the Partnership's 2002 cash flows from operations, investing or
     financing activities.

     The  change  had the following effects on the Statement of  Operations
     for the three and nine months ended September 30, 2002.

                           Three Months Ended      Nine Months Ended
                                  (1)
                                    Previousl               Previousl
                                        y                       y
                          Restated   Reported     Restated  Reported
  Depreciation,
  depletion and
  amortization                           $        21,000    21,000
                                    7,000
  Income before                     63,558        100,369   100,369
  cumulative effect
Cumulative effect of
  change in
  accounting principle              -             (55,000)  -
  Net income                        63,558        45,369    100,369
  Net income allocated
  to:
  Managing General                  6,350         10,923    10,923
  Partner
  General partner                   706           1,214     1,214
  Limited partners                  56,502        33,232    88,232
   Income per limited
  partner
     unit before                         5.05
  cumulative effect                               7.89      7.89
   Cumulative effect
  per limited
     partner unit                        -                       -
                                                  (4.92)
   Net income per
  limited
     partner unit                        5.05       2.97      7.89

(1) There was  no  effect  due  to the change in depletion  method  on  the
          quarter ended September 30, 2002.


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

General
Southwest Royalties Institutional Income Fund X-B, L.P. was organized as  a
Delaware  limited  partnership on November 27, 1990. The offering  of  such
limited  partnership interests began December 1, 1990 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  March 11, 1991, with the offering of limited partnership interests
concluding September 30, 1991, with total limited partner contributions  of
$5,590,500.

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 anticipates performing  drilling
projects  and  workovers  during  the  years  2003  and  2004  to   enhance
production.  The Partnership may have an increase in production volumes for
the  years  2003  and  2004; otherwise, the Partnership  will  most  likely
experience the historical production decline, which has approximated 8% per
year.

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

In  the  fourth  quarter  of  2002,  the  Partnership  changed  methods  of
accounting  for  depletion of capitalized costs from  the  units-of-revenue
method  to  the  units-of-production method.  The newly adopted  accounting
principle   is  preferable  in  the  circumstances  because  the  units-of-
production method results in a better matching of the costs of oil and  gas
production  against  the related revenue received in  periods  of  volatile
prices   for  production  as  have  been  experienced  in  recent  periods.
Additionally, the units-of-production method is the predominant method used
by full cost companies in the oil and gas industry, accordingly, the change
improves  the comparability of the Partnership's financial statements  with
its peer group.

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, 2003, the net capitalized costs  did
not exceed the estimated present value of oil and gas reserves.


The  Partnership's  interest  in oil and gas  properties  consists  of  net
profits  interests  in  proved properties located  within  the  continental
United  States.   A net profits interest is created when  the  owner  of  a
working  interest in a property enters into an arrangement  providing  that
the  net profits interest owner will receive a stated percentage of the net
profit  from  the  property.   The  net profits  interest  owner  will  not
otherwise participate in additional costs and expenses of the property.

The  Partnership recognizes income from its net profits interest in oil and
gas property on an accrual basis, while the quarterly cash distributions of
the net profits interest are based on a calculation of actual cash received
from  oil  and  gas sales, net of expenses incurred during  that  quarterly
period.   If  the  net  profits interest calculation  results  in  expenses
incurred  exceeding the oil and gas income received during  a  quarter,  no
cash  distribution is due to the Partnership's net profits  interest  until
the  deficit is recovered from future net profits.  The Partnership accrues
a quarterly loss on its net profits interest provided there is a cumulative
net amount due for accrued revenue as of the balance sheet date.

Critical Accounting Policies

Full cost ceiling calculations The Partnership follows the full cost method
of  accounting  for  its  oil and gas properties.   The  full  cost  method
subjects  companies to quarterly calculations of a "ceiling", or limitation
on  the  amount of properties that can be capitalized on the balance sheet.
If  the  Partnership's capitalized costs are in excess  of  the  calculated
ceiling, the excess must be written off as an expense.

The  Partnership's discounted present value of its proved oil  and  natural
gas  reserves  is  a  major  component  of  the  ceiling  calculation,  and
represents  the  component  that requires the  most  subjective  judgments.
Estimates  of  reserves are forecasts based on engineering data,  projected
future  rates  of  production and the timing of future  expenditures.   The
process  of  estimating oil and natural gas reserves  requires  substantial
judgment,  resulting  in  imprecise determinations,  particularly  for  new
discoveries.   Different reserve engineers may make different estimates  of
reserve  quantities  based  on the same data.   The  Partnership's  reserve
estimates are prepared by outside consultants.

The  passage  of  time  provides  more  qualitative  information  regarding
estimates of reserves, and revisions are made to prior estimates to reflect
updated  information.   However,  there  can  be  no  assurance  that  more
significant  revisions  will not be necessary in  the  future.   If  future
significant  revisions  are  necessary  that  reduce  previously  estimated
reserve quantities, it could result in a full cost property writedown.   In
addition to the impact of these estimates of proved reserves on calculation
of  the  ceiling,  estimates  of proved reserves  are  also  a  significant
component of the calculation of DD&A.

While  estimating  the  quantities of proved reserves  require  substantial
judgment,  the associated prices of oil and natural gas reserves  that  are
included  in  the discounted present value of the reserves do  not  require
judgment.  The ceiling calculation dictates that prices and costs in effect
as  of the last day of the period are generally held constant indefinitely.
Because  the ceiling calculation dictates that prices in effect as  of  the
last  day  of  the  applicable quarter are held constant indefinitely,  the
resulting  value  may  not be indicative of the  true  fair  value  of  the
reserves.  Oil and natural gas prices have historically been cyclical  and,
on  any particular day at the end of a quarter, can be either substantially
higher or lower than the Partnership's long-term price forecast that  is  a
barometer for true fair value.

In  the  fourth  quarter  of  2002,  the  Partnership  changed  methods  of
accounting  for  depletion of capitalized costs from  the  units-of-revenue
method  to  the  units-of-production method.  The newly adopted  accounting
principle   is  preferable  in  the  circumstances  because  the  units-of-
production method results in a better matching of the costs of oil and  gas
production  against  the related revenue received in  periods  of  volatile
prices   for  production  as  have  been  experienced  in  recent  periods.
Additionally, the units-of-production method is the predominant method used
by full cost companies in the oil and gas industry, accordingly, the change
improves  the comparability of the Partnership's financial statements  with
its peer group.


Results of Operations

A.  General Comparison of the Quarters Ended September 30, 2003 and 2002

The  following  table  provides certain information  regarding  performance
factors for the quarters ended September 30, 2003 and 2002:

                                    Three Months
                                       Ended         Percenta
                                                        ge
                                   September 30,     Increase
                                   2003      2002    (Decreas
                                                        e)
                                   ----      ----    --------
                                                        --
Average price per barrel  of  $   29.17              9%
oil                                        26.74
Average price per mcf of gas  $    4.11              47%
                                           2.80
Oil production in barrels        4,650     5,100     (9%)
Gas production in mcf            16,500    17,600    (6%)
Income   from  net   profits  $  29,906    86,970    (66%)
interests
Partnership distributions     $  -         50,000    (100%)
Limited              partner  $  -         45,000    (100%)
distributions
Per  unit  distribution   to
limited
 partners                     $       -              (100%)
                                           4.02
Number  of  limited  partner     11,181    11,181
units

Revenues

The  Partnership's income from net profits interests decreased  to  $29,906
from   $86,970  for  the  quarters  ended  September  30,  2003  and  2002,
respectively,  a  decrease  of 66%.  The principal  factors  affecting  the
comparison  of  the  quarters ended September 30,  2003  and  2002  are  as
follows:

1.   The  average  price  for a barrel of oil received by  the  Partnership
     increased  during the quarter ended September 30, 2003 as compared  to
     the  quarter  ended  September 30, 2002 by 9%, or  $2.43  per  barrel,
     resulting in an increase of approximately $11,300 in income  from  net
     profits  interests.  Oil sales represented 67% of total  oil  and  gas
     sales  during the quarter ended September 30, 2003 as compared to  73%
     during the quarter ended September 30, 2002.

     The  average  price  for  an mcf of gas received  by  the  Partnership
     increased  during the same period by 47%, or $1.31 per mcf,  resulting
     in  an  increase of approximately $21,600 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
     $32,900.  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.



2. Oil  production  decreased approximately 450 barrels or  9%  during  the
   quarter  ended  September  30, 2003 as compared  to  the  quarter  ended
   September 30, 2002, resulting in a decrease of approximately $12,000  in
   income from net profits interests.

    Gas  production decreased approximately 1,100 mcf or 6% during the same
    period, resulting in a decrease of approximately $3,100 in income  from
    net profits interests.

    The decrease in income from net profits interests due to the change  in
    production is approximately $15,100.

3.  Lease  operating  costs  and  production  taxes  were  76%  higher,  or
    approximately $74,900 more during the quarter ended September 30,  2003
    as  compared to the quarter ended September 30, 2002.  The increase  in
    lease  operating  expense  s  due to one  lease  that  a  workover  was
    performed  during the quarter ended September 30, 2003 to remove  stuck
    tubing  out  of  the  hole.  In addition four wells  were  plugged  and
    abandoned.

Costs and Expenses

Total costs and expenses increased to $31,334 from $27,260 for the quarters
ended  September 30, 2003 and 2002, respectively, an increase of 15%.   The
increase  is a direct result of the accretion expense associated  with  our
long  term liability related to expected abandonment costs of our  oil  and
natural  gas  properties,  general  and administrative  expense,  partially
offset by a decrease in 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 increased 6%
    or  approximately $1,300 during the quarter ended September 30, 2003 as
    compared  to  the  quarter ended September 30, 2002.  The  increase  in
    general and administrative expense is due to an increase in independent
    accounting review and audit fees.

2.  Depletion  expense decreased to $6,000 for the quarter ended  September
    30,  2003  from $7,000 for the same period in 2002.  This represents  a
    decrease  of  14%.   In  the fourth quarter of  2002,  the  Partnership
    changed  methods of accounting for depletion of capitalized costs  from
    the  units-of-revenue  method to the units-of-production  method.   The
    newly  adopted  accounting principle is preferable in the circumstances
    because the units-of-production method results in a better matching  of
    the  costs  of  oil  and  gas production against  the  related  revenue
    received  in  periods of volatile prices for production  as  have  been
    experienced  in  recent periods.  Additionally, the units-of-production
    method is the predominant method used by full cost companies in the oil
    and gas industry, accordingly, the change improves the comparability of
    the Partnership's financial statements with its peer group (See Note  4
    of the notes to the financial statements).




B.   General Comparison of the Nine Month Periods Ended September 30,  2003
and 2002

The  following  table  provides certain information  regarding  performance
factors for the nine month periods ended September 30, 2003 and 2002:

                               Nine Months
                                  Ended         Percenta
                                                   ge
                              September 30,     Increase
                              2003      2002    (Decreas
                                                   e)
                              ----      ----    --------
                                                   --
Average    price    per  $   30.36              30%
barrel of oil                         23.33
Average  price per  mcf  $    4.76              87%
of gas                                2.54
Oil    production    in     14,550    15,000    (3%)
barrels
Gas production in mcf       47,900    51,300    (7%)
Income from net profits  $  209,809   176,030   19%
interests
Partnership              $  170,000   100,000   70%
distributions
Limited         partner  $  153,000   90,000    70%
distributions
Per  unit  distribution
to limited
 partners                $   13.68              70%
                                      8.05
Number    of    limited     11,181    11,181
partner units

Revenues

The  Partnership's income from net profits interests increased to  $209,809
from  $176,030  for  the nine months ended September  30,  2003  and  2002,
respectively,  a  increase  of 19%.  The principal  factors  affecting  the
comparison  of  the nine months ended September 30, 2003 and  2002  are  as
follows:

1.  The  average  price  for a barrel of oil received  by  the  Partnership
    increased  during the nine months ended September 30, 2003 as  compared
    to  the  nine  months ended September 30, 2002 by  30%,  or  $7.03  per
    barrel,  resulting in an increase of approximately $102,300  in  income
    from net profits interests.  Oil sales represented 66% of total oil and
    gas  sales  during  the nine months ended September 30,  2003  and  73%
    during the nine months ended September 30, 2002.

    The  average  price  for  an  mcf of gas received  by  the  Partnership
    increased during the same period by 87%, or $2.22 per mcf, resulting in
    an  increase  of  approximately $106,300 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
    $208,600.  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.



2.  Oil  production decreased approximately 450 barrels or  3%  during  the
    nine  months  ended September 30, 2003 as compared to the  nine  months
    ended  September  30,  2002, resulting in a decrease  of  approximately
    $10,500 in income from net profits interests.

    Gas  production decreased approximately 3,400 mcf or 7% during the same
    period, resulting in a decrease of approximately $8,600 in income  from
    net profits interests.

    The  total  decrease in income from net profits interests  due  to  the
    change in production is approximately $19,100.

3.    Lease  operating  costs  and production taxes  were  51%  higher,  or
   approximately $155,500 more during the nine months ended September 30, 2003
   as compared to the nine months ended September 30, 2002. The increase in
   lease operating expense s due to one lease that a workover was performed
   during the nine months ended September 30, 2003 to remove stuck tubing out
   of the hole.  In addition four wells were plugged and abandoned.

Costs and Expenses

Total  costs  and expenses increased to $97,210 from $79,748 for  the  nine
months ended September 30, 2003 and 2002, respectively, an increase of 22%.
The  increase  is a direct result of the accretion expense associated  with
our  long term liability related to expected abandonment costs of  our  oil
and  natural gas properties, general and administrative expense,  partially
offset by an decrease in 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 increased 15% or
   approximately $8,900 during the nine months ended September 30, 2003  as
   compared  to the nine months ended September 30, 2002.  The increase  in
   general  and administrative expense is due to an increase in independent
   accounting review and audit fees.

2.  Depletion  expense  decreased to $18,000  for  the  nine  months  ended
    September  30,  2003 from $21,000 for the same period  in  2002.   This
    represents  a  decrease of 14%.  In the fourth  quarter  of  2002,  the
    Partnership  changed methods of accounting for depletion of capitalized
    costs  from  the  units-of-revenue method  to  the  units-of-production
    method.   The newly adopted accounting principle is preferable  in  the
    circumstances  because  the units-of-production  method  results  in  a
    better  matching  of  the costs of oil and gas production  against  the
    related  revenue received in periods of volatile prices for  production
    as have been experienced in recent periods.  Additionally, the units-of-
    production method is the predominant method used by full cost companies
    in  the  oil  and  gas industry, accordingly, the change  improves  the
    comparability of the Partnership's financial statements with  its  peer
    group.  The change in method had no effect on depletion expense for the
    nine  months ended September 30, 2002 however; it decreased net  income
    for  the nine months ended September 30, 2002 by $55,000(See Note 4  of
    the notes to the financial statements).

Cumulative effect of change in accounting principle

On  January  1,  2003,  the  Partnership  adopted  Statement  of  Financial
Accounting  Standards No. 143, Accounting for Asset Retirement  Obligations
("SFAS  No. 143").  Adoption of SFAS No. 143 is required for all  companies
with fiscal years beginning after June 15, 2002.  The new standard requires
the Partnership to recognize a liability for the present value of all legal
obligations  associated with the retirement of tangible  long-lived  assets
and to capitalize an equal amount as a cost of the asset and depreciate the
additional cost over the estimated useful life of the asset.  On January 1,
2003,  the  Partnership  recorded  additional  costs,  net  of  accumulated
depreciation,  of  approximately  $101,341,  a  long  term   liability   of
approximately  $192,765  and  a  loss  of  approximately  $91,424  for  the
cumulative  effect  on depreciation of the additional costs  and  accretion
expense  on the liability related to expected abandonment costs of its  oil
and  natural  gas producing properties.  At September 30, 2003,  the  asset
retirement  obligation was $202,000, and the increase in the  balance  from
January 1, 2003 of $11,522 is due to accretion expense, partially offset by
the  plug  and  abandonment of oil and gas properties, which decreased  the
asset retirement obligation by $2,287.  The pro forma amounts for the three
and  nine months ended September 30, 2002, which are presented on the  face
of  the  statements  of  operations,  reflect  the  effect  of  retroactive
application of SFAS No. 143.



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 $146,700  in
the  nine  months  ended  September 30, 2003 as compared  to  approximately
$102,000  in the nine months ended September 30, 2002.  The primary  source
of the 2003 cash flow from operating activities was profitable operations.

Cash flows used in financing activities were approximately $169,700 in  the
nine  months ended September 30, 2003 as compared to approximately $100,000
in  the  nine  months ended September 30, 2002.  The only use in  financing
activities was the distributions to partners.

Total  distributions during the nine months ended September 30,  2003  were
$170,000  of  which  $153,000 was distributed to the limited  partners  and
$17,000  to  the  general partners.  The per unit distribution  to  limited
partners during the nine months ended September 30, 2003 was $13.68.  Total
distributions during the nine months ended September 30, 2002 were $100,000
of which $90,000 was distributed to the limited partners and $10,000 to the
general partners.  The per unit distribution to limited partners during the
nine months ended September 30, 2002 was $8.05.

The  source  for  the  2003  distributions of $170,000  were  oil  and  gas
operations of approximately $146,700, with the balance from available  cash
on  hand  at  the  beginning  of  the  period.  The  source  for  the  2002
distributions  of  $100,000  were oil and gas operations  of  approximately
$102,000,   resulting  in  excess  cash  for  contingencies  or  subsequent
distributions.

Since  inception  of  the  Partnership, cumulative  cash  distributions  of
$5,845,352  have  been  made to the partners.  As of  September  30,  2003,
$5,319,860 or $475.79 per limited partner unit has been distributed to  the
limited partners, representing a 95% return of the capital contributed.

As  of  September 30, 2003, the Partnership had approximately  $115,900  in
working  capital.   The  Managing  General  Partner  knows  of  no  unusual
contractual  commitments.  Although the partnership  held  many  long-lived
properties   at  inception,  because  of  the  restrictions   on   property
development  imposed by the partnership agreement, the  Partnership  cannot
develop   its   non-producing  properties,  if  any.    Without   continued
development,  the producing reserves continue to deplete.  Accordingly,  as
the  Partnership's properties have matured and depleted, the net cash flows
from  operations  for  the  partnership has steadily  declined,  except  in
periods  of  substantially  increased commodity  pricing.   Maintenance  of
properties  and administrative expenses for the Partnership are  increasing
relative to production.  As the properties continue to deplete, maintenance
of  properties  and administrative costs as a percentage of production  are
expected to continue to increase.

The  Managing General Partner has examined various alternatives to  address
the  issue of depleting producing reserves.  Continuing operations  exposes
the   partnership  to  an  inevitable  decline  in  operating  results  and
distributions  of  cash.   Liquidating  the  partnership  would  result  in
immediate  realization of cash for limited partners,  but  prices  paid  by
purchasers  of Partnership property in liquidation would likely  include  a
substantial discount for risks and uncertainties of future cash  flows,  as
well  as any development risks.  After reviewing various alternatives,  the
Managing General Partner initiated a plan to merge the Partnership  and  20
other limited partnerships with and into the Managing General Partner.   On
October  17,  2002,  the  Managing General  Partner  filed  a  Registration
Statement on Form S-4 with the Securities and Exchange Commission  relating
to  this proposed merger.  There is no assurance, however, that this merger
will  be consummated.  Currently the Managing General Partner is evaluating
whether or not to continue to pursue the proposed merger.



Liquidity - Managing General Partner
In  previous  reports  the Partnership provided that the  Managing  General
Partner  had  $124.0  million  of principal  scheduled  to  mature  between
December 31, 2002 and December 31, 2004.  Subsequent to September 30,  2003
the   Managing  General  Partner  refinanced  the  majority  of  its   debt
obligations and currently has $71.7 million in debt scheduled to mature  on
June  1, 2006 and $40.0 million in debt scheduled to mature on October  15,
2008.   The  Managing General Partner believes that it  has  adequate  cash
flows to meet its debt principal maturities scheduled for 2004.

Recent Accounting Pronouncements

The  FASB  has  issued Statement No. 143 "Accounting for  Asset  Retirement
Obligations" which establishes requirements for the accounting of  removal-
type  costs  associated with asset retirements.  The standard is  effective
for  fiscal  years beginning after June 15, 2002, with earlier  application
encouraged.   This statement has been adopted by the Partnership  effective
January 1, 2003.  The transition adjustment resulting from the adoption  of
SFAS  No.  143  has been reported as a cumulative effect  of  a  change  in
accounting principle.

In  April 2003, the FASB issued Statement of Financial Accounting Standards
No.  149,  Amendment  of  Statement No. 133 on Derivative  Instruments  and
Hedging Activities ("SFAS No. 149").  SFAS No. 149 amendments require  that
contracts  with  comparable  characteristics be  accounted  for  similarly,
clarifies   when   a  contract  with  an  initial  investment   meets   the
characteristic  of  a  derivative and clarifies when a derivative  requires
special  reporting  in  the  statement of cash  flows.   SFAS  No.  149  is
effective  for  hedging relationships designated and for contracts  entered
into or modified after June 30, 2003, except for provisions that relate  to
SFAS  No. 133 Statement Implementation Issues that have been effective  for
fiscal  quarters  prior to June 15, 2003, should be applied  in  accordance
with  their  respective effective dates and certain provisions relating  to
forward  purchases or sales of when-issued securities or  other  securities
that  do not yet exist, should be applied to existing contracts as well  as
new contracts entered into after June 30, 2003.  Assessment by the Managing
General  Partner  revealed this pronouncement to  have  no  impact  on  the
Partnership.

In  May  2003, the FASB issued Statement of Financial Accounting  Standards
No.150,  Accounting for Certain Financial Instruments with  Characteristics
of  both  Liabilities  and  Equity  ("SFAS  150").   SFAS  150  establishes
standards  for  how  an  issuer classifies and measures  certain  financial
instruments  with  characteristics of  both  liabilities  and  equity.   It
requires that an issuer classify a financial instrument that is within  the
scope of SFAS 150 as a liability (or an asset in some circumstances).  Many
of those instruments were previously classified as equity.  The application
of  SFAS 150 is not expected to have a material effect on the Partnership's
consolidated  financial  statements.   This  Statement  is  effective   for
financial  instruments entered into or modified after  May  31,  2003,  and
otherwise  is  effective  at  the beginning of  the  first  interim  period
beginning after June 15, 2003.




Item 3.   Quantitative and Qualitative Disclosures About Market Risk

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

Item 4.   Controls and Procedures

(a)   Evaluation  of  Disclosure  Controls  and  Procedures.   The   senior
management of the Partnership's Managing General Partner is responsible for
establishing and maintaining a system of disclosure controls and procedures
(as defined in Rule 13a-14 and 15d-14 under the Securities Exchange Act  of
1934 (the "Exchange Act")) designed to ensure that information required  to
be  disclosed  by the Partnership in the reports that it files  or  submits
under  the  Exchange Act is recorded, processed, summarized  and  reported,
within   the  time  periods  specified  in  the  Securities  and   Exchange
Commission's rules and forms.  Disclosure controls and procedures  include,
without  limitation,  controls  and  procedures  designed  to  ensure  that
information required to be disclosed by the issuer in the reports  that  it
files or submits under the Exchange Act is accumulated and communicated  to
the  issuer's  management,  including its principal  executive  officer  of
officers  and principal financial officer or officers, or person performing
similar  functions,  as  appropriate to allow  timely  decisions  regarding
required disclosure.

In  accordance  with Exchange Act Rules 13a-15 and 15d-15, the  Partnership
carried  out  an evaluation, with the participation of the Chief  Executive
Officer  and  Chief Financial Officer of the Managing General  Partner,  as
well as other key members of the Managing General Partner's management,  of
the  effectiveness of the Partnership's disclosure controls and  procedures
as  of  the  end  of  the  period covered by this report.   Based  on  that
evaluation,  the  Managing General Partner's Chief  Executive  Officer  and
Chief   Financial  Officer  concluded  that  the  Partnership's  disclosure
controls and procedures were effective, as of the end of the period covered
by  this  report, to provide reasonable assurance that information required
to  be disclosed in the Partnership's reports filed or submitted under  the
Exchange  Act  is recorded, processed, summarized and reported  within  the
time  periods  specified in the Securities and Exchange Commission's  rules
and forms.

(b) Changes in Internal Controls.  There have not been any changes
in the Partnership's
internal controls over financial reporting identified in connection
with the evaluation
described  above  that occurred during the Partnership's last fiscal
quarter  that  has
materially  affected,  or  is reasonably likely to materially  affect,
these  internal
controls over financial reporting.



                        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:

               31.1 Rule 13a-14(a)/15d-14(a) Certification
31.2 Rule 13a-14(a)/15d-14(a) Certification
               32.1 Certification of Chief Executive Officer Pursuant to
18 U.S.C. Section
                  1350, as
                  adopted  Pursuant  to Section 906 of  the  Sarbanes-Oxley
                  Act of 2002
               32.2 Certification of Chief Financial Officer Pursuant to
 18 U.S.C. Section
                  1350, as
                  adopted  Pursuant  to Section 906 of  the  Sarbanes-Oxley
                  Act of 2002

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






                                SIGNATURES


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

                                   Southwest Royalties Institutional
                                   Income Fund X-B, L.P.
                                   a Delaware limited partnership

                                   By:  Southwest Royalties, Inc.
                                        Managing General Partner


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

Date:     November 14, 2003



                    SECTION 302 CERTIFICATION                Exhibit 31.1


I, H.H. Wommack, III, certify that:

1.   I  have  reviewed  this quarterly report on  Form  10-Q  of  Southwest
Royalties Institutional Income Fund X-B, L.P.

2.Based  on my knowledge, this report does not contain any untrue statement
  of  a  material fact or omit to state a material fact necessary  to  make
  the  statements  made,  in light of the circumstances  under  which  such
  statements  were made, not misleading with respect to the period  covered
  by this report;

3.Based  on  my  knowledge, the financial statements, and  other  financial
  information  included  in  this report, fairly present  in  all  material
  respects  the financial condition, results of operations and  cash  flows
  of the registrant as of, and for, the periods presented in this report;

4.The  registrant's other certifying officer(s) and I are  responsible  for
  establishing  and  maintaining disclosure  controls  and  procedures  (as
  defined  in  Exchange  Act  Rules 13a-15(e) and  15-15(e))  and  internal
  control  over financial reporting (as defined in Exchange Act Rules  13a-
  15(f) and 15d-15(f) for the registrant and have:

  a)Designed  such  disclosure  controls and  procedures,  or  caused  such
     disclosure   controls  and  procedures  to  be  designed   under   our
     supervision,  to  ensure  that material information  relating  to  the
     registrant, including its consolidated subsidiaries, is made known  to
     us  by others within those entities, particularly during the period in
     which this report is being prepared;

  b)Designed  such  internal control over financial  reporting,  or  caused
     such  internal  control over financial reporting to be designed  under
     our   supervision,  to  provide  reasonable  assurance  regarding  the
     reliability  of financial reporting and the preparation  of  financial
     statements for external purposes in accordance with generally accepted
     accounting principles;

  c)Evaluated  the  effectiveness of the registrant's  disclosure  controls
     and  procedures and presented in this report our conclusions about the
     effectiveness of the disclosure controls and procedures, as of the end
     of the period covered by this report based on such evaluation; and

  d)Disclosed  in  this  report  any change in  the  registrant's  internal
     control over financial reporting that occurred during the registrant's
     most recent fiscal quarter (the registrant's fourth fiscal quarter  in
     the  case  of  an annual report) that has materially affected,  or  is
     reasonably  likely  to  materially affect, the  registrant's  internal
     control over financial reporting; and

5.The  registrant's other certifying officer(s) and I have disclosed, based
  on  our  most  recent  evaluation  of  internal  control  over  financial
  reporting,  to  the  registrant's auditors and  the  audit  committee  of
  registrant's  board  of directors (or persons performing  the  equivalent
  functions):

  a)All  significant deficiencies and material weaknesses in the design  or
     operation   of  internal  controls  over  financial  reporting   which
     reasonably  likely  to  adversely affect the registrant's  ability  to
     record, process, summarize and report financial information; and

  b)Any  fraud, whether or not material, that involves management or  other
     employees  who  have  a significant role in the registrant's  internal
     controls over financial reporting.


Date:  November 14, 2003           /s/ H.H. Wommack, III
                                   H. H. Wommack, III
                                    Chairman, President and Chief Executive
Officer
                                   of Southwest Royalties, Inc., the
                                   Managing General Partner of
                                   Southwest Royalties Institutional Income
Fund X-B, L.P.




                    SECTION 302 CERTIFICATION                Exhibit 31.2


I, Bill E. Coggin, certify that:

1.   I  have  reviewed  this quarterly report on  Form  10-Q  of  Southwest
Royalties Institutional Income Fund X-B, L.P.

2.Based  on my knowledge, this report does not contain any untrue statement
  of  a  material fact or omit to state a material fact necessary  to  make
  the  statements  made,  in light of the circumstances  under  which  such
  statements  were made, not misleading with respect to the period  covered
  by this report;

3.Based  on  my  knowledge, the financial statements, and  other  financial
  information  included  in  this report, fairly present  in  all  material
  respects  the financial condition, results of operations and  cash  flows
  of the registrant as of, and for, the periods presented in this report;

4.The  registrant's other certifying officer(s) and I are  responsible  for
  establishing  and  maintaining disclosure  controls  and  procedures  (as
  defined  in  Exchange  Act  Rules 13a-15(e) and  15-15(e))  and  internal
  control  over financial reporting (as defined in Exchange Act Rules  13a-
  15(f) and 15d-15(f) for the registrant and have:

  a)Designed  such  disclosure  controls and  procedures,  or  caused  such
     disclosure   controls  and  procedures  to  be  designed   under   our
     supervision,  to  ensure  that material information  relating  to  the
     registrant, including its consolidated subsidiaries, is made known  to
     us  by others within those entities, particularly during the period in
     which this report is being prepared;

  b)Designed  such  internal control over financial  reporting,  or  caused
     such  internal  control over financial reporting to be designed  under
     our   supervision,  to  provide  reasonable  assurance  regarding  the
     reliability  of financial reporting and the preparation  of  financial
     statements for external purposes in accordance with generally accepted
     accounting principles;

  c)Evaluated  the  effectiveness of the registrant's  disclosure  controls
     and  procedures and presented in this report our conclusions about the
     effectiveness of the disclosure controls and procedures, as of the end
     of the period covered by this report based on such evaluation; and

  d)Disclosed  in  this  report  any change in  the  registrant's  internal
     control over financial reporting that occurred during the registrant's
     most recent fiscal quarter (the registrant's fourth fiscal quarter  in
     the  case  of  an annual report) that has materially affected,  or  is
     reasonably  likely  to  materially affect, the  registrant's  internal
     control over financial reporting; and

5.The  registrant's other certifying officer(s) and I have disclosed, based
  on  our  most  recent  evaluation  of  internal  control  over  financial
  reporting,  to  the  registrant's auditors and  the  audit  committee  of
  registrant's  board  of directors (or persons performing  the  equivalent
  functions):

  a)All  significant deficiencies and material weaknesses in the design  or
     operation   of  internal  controls  over  financial  reporting   which
     reasonably  likely  to  adversely affect the registrant's  ability  to
     record, process, summarize and report financial information; and

  b)Any  fraud, whether or not material, that involves management or  other
     employees  who  have  a significant role in the registrant's  internal
     controls over financial reporting.


Date:  November 14, 2003           /s/ Bill E. Coggin
                                   Bill E. Coggin
                                   Executive Vice President
                                   and Chief Financial Officer of
                                   Southwest Royalties, Inc., the
                                   Managing General Partner of
                                   Southwest Royalties Institutional Income
Fund X-B, L.P.





           CERTIFICATION PURSUANT TO               Exhibit 32.1
                          19 U.S.C. SECTION 1350,
                          AS ADOPTED PURSUANT TO
               SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002


      In  connection  with  the  Quarterly Report  of  Southwest  Royalties
Institutional Income Fund X-B, Limited Partnership (the "Company") on  Form
10-Q  for the period ending September 30, 2003 as filed with the Securities
and Exchange Commission on the date hereof (the "Report"), I, H.H. Wommack,
III,  Chief  Executive  Officer  of the Managing  General  Partner  of  the
Company,  certify,  pursuant to 18 U.S.C.  1350,  as  adopted  pursuant  to
906 of the Sarbanes-Oxley Act of 2002, that:

  (1)   The Report fully complies with the requirements of section 13(a) or
     15(d) of the Securities Exchange Act of 1934; and

  (2)   The  information  contained in the Report fairly presents,  in  all
     material respects, the financial condition and results of operation of the
     Company.


Date:  November 14, 2003




/s/ H.H. Wommack, III
H. H. Wommack, III
Chairman, President, Director and Chief Executive Officer
  of Southwest Royalties, Inc., the
  Managing General Partner of
  Southwest Royalties Institutional Income Fund X-B, L.P.


              CERTIFICATION PURSUANT TO               Exhibit 32.2
                          19 U.S.C. SECTION 1350,
                          AS ADOPTED PURSUANT TO
               SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002


    In   connection  with  the  Quarterly  Report  of  Southwest  Royalties
Institutional Income Fund X-B, Limited Partnership (the "Company") on  Form
10-Q  for the period ending September 30, 2003 as filed with the Securities
and  Exchange  Commission on the date hereof (the  "Report"),  I,  Bill  E.
Coggin,  Chief  Financial Officer of the Managing General  Partner  of  the
Company,  certify,  pursuant to 18 U.S.C.  1350,  as  adopted  pursuant  to
906 of the Sarbanes-Oxley Act of 2002, that:

  (1)   The Report fully complies with the requirements of section 13(a) or
     15(d) of the Securities Exchange Act of 1934; and

  (2)   The  information  contained in the Report fairly presents,  in  all
     material respects, the financial condition and results of operation of the
     Company.


Date:  November 14, 2003




/s/ Bill E. Coggin
Bill E. Coggin
Executive Vice President
  and Chief Financial Officer of
  Southwest Royalties, Inc., the
  Managing General Partner of
  Southwest Royalties Institutional Income Fund X-B, L.P.