455804


                            UNITED STATES
                 SECURITIES AND EXCHANGE COMMISSION
                       Washington, D.C.  20549

                               FORM 15

CERTIFICATION AND NOTICE OF TERMINATION OF REGISTRATION UNDER SECTION
12(g) OF THE SECURITIES EXCHANGE ACT OF 1934 OR SUSPENSION OF DUTY TO
FILE REPORTS UNDER SECTIONS 13 AND 15(d) OF THE SECURITIES EXCHANGE
ACT OF 1934.

                Commission File Number:  033-47668-02

      Southwest Royalties Institutional Income Fund XI-B, L.P.
       (Exact name of registrant as specified in its charter)

 407 N. Big Spring, Suite 300, Midland, Texas 79701, (432) 686-9927
(Address, including zip code, and telephone number, including area
code, of registrants principal executive offices)

                    Limited Partnership Interests
      (Title of each class of securities covered by this Form)

                                None
(Title of all other classes of securities for which a duty to file
reports under section 13(a) or 15(d) remains)

     Please place an X in the box(es) to designate the appropriate
rule provision(s) relied upon to terminate or suspend the duty to
file reports:

     Rule 12g-4(a)(1)(i) X         Rule 12h-3(b)(1)(i) X
     Rule 12g-4(a)(1)(ii)          Rule 12h-3(b)(1)(ii)
     Rule 12g-4(a)(2)(i)           Rule 12h-3(b)(2)(i)
     Rule 12g-4(a)(2)(ii)          Rule 12h-3(b)(2)(ii)
                                   Rule 15d-6


     Approximate number of holders of record as of the certification
     or notice date: 176 holders of record.

     Pursuant to the requirements of the Securities Exchange Act of
1934, Southwest Royalties Institutional Income Fund XI-B, L.P., has
caused this certification/notice to be signed on its behalf by the
undersigned duly authorized person.


Date:     July 14, 2004       By:      /s/ Mel G. Riggs
                                   Name:     Mel G. Riggs
                                   Title:    Vice President
                              of Southwest
                                       Royalties, Inc.,
                              General Partner