Form 8-K - Larclay Transaction.DOC
                          UNITED STATES
               SECURITIES AND EXCHANGE COMMISSION
                     Washington, D.C. 20549


                            FORM 8-K


                         CURRENT REPORT
Pursuant to Section 13 or 15(d) of the Securities Exchange Act of
                              1934



  Date of Report (Date of earliest event reported): May 4, 2006

            Southwest Oil & Gas Income Fund X-B, L.P.
     (Exact name of registrant as specified in its charter)


      Delaware              0-19585              75-2332176
  (State or other         (Commission          (IRS Employer
  jurisdiction of         File Number)      Identification No.)
   incorporation)


                    6 Desta Drive, Suite 6500
                   Midland, Texas  79705-5510
   (Address of principal executive offices including zip code)

       Registrant's telephone number, including area code:
                         (432) 682-6324

Check the appropriate box below if the Form 8-K filing is
intended to simultaneously satisfy the filing obligation of the
registrant under any of the following provisions (see General
Instruction A.2. below):

 Written communications pursuant to Rule 425 under the Securities
Act (17 CFR 230.425)

 Soliciting material pursuant to Rule 14a-12 under the Exchange
Act (17 CFR 240.14a-12)

 Pre-commencement communications pursuant to Rule 14d-2(b) under
the Exchange Act (17 CFR
    240.14d-2(b))

 Pre-commencement communications pursuant to Rule 13e-4(c) under
the Exchange Act (17 CFR
    240.13e-4(c))




Item 3.03  Material Modification to Rights of Security Holders

On May 4, 2006, Southwest Oil & Gas Income Fund X-B, L.P. (the
"Partnership") entered into an agreement (the "Agreement") with
Southwest Royalties, Inc. (the "Company"), the Managing General
Partner of the Partnership, to provide that the holders of a
majority in interest of limited partnership interests or units in
the Partnership, other than the Company and its affiliates (the
"Unaffiliated Holders"), could vote to remove the Company as
general partner of the Partnership.  The Agreement generally
requires the Company to abstain from voting any limited
partnership interests now owned or hereafter acquired by the
Company on the removal of the Company as general partner of the
Partnership.  However, if the Unaffiliated Holders voting for or
in favor of the removal of the Company as general partner do not
constitute a majority in interest of the limited partners and
would constitute a majority in interest of the limited partners
if the limited partnership interests held by the Company were not
included in calculating a majority interest, the agreement
provides that the Company shall vote its interests for or in
favor of the removal of the Company as general partner.

By entering into this Agreement, the Company and the Partnership
intend to grant the Unaffiliated Holders the right to vote to
remove the Company as general partner of the Partnership without
the necessity of the concurrence of the Company.

Item 9.01.     Financial Statements and Exhibits.

(d)  Exhibits.

   4.1        Agreement dated May 4, 2006 between Southwest
              Royalties, Inc. and Southwest Oil & Gas Income
              Fund X-B, L.P.
                           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 hereunto duly authorized.

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


May 8, 2006                   By:    /s/  L. Paul Latham
                           L Paul Latham
                           President and Chief Executive Officer
of
                           Southwest Royalties, Inc., General
Partner of
                           Southwest Oil & Gas Income Fund X-B,
L.P.


May 8, 2006                   By:   /s/ Mel G. Riggs
                           Mel G. Riggs
                           Vice President and Chief Financial
Officer of
                           Southwest Royalties, Inc., General
Partner of
                           Southwest Oil & Gas Income Fund X-B,
L.P.