**UNITED
      STATES**


**SECURITIES
      AND EXCHANGE COMMISSION**


**Washington,
      D.C. 20549**








**FORM
      10-K**








**[X]
      ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT
      OF
      1934**





For
      the
      fiscal year ended December 31, 2005


or





**[  
      ] TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES AND
      EXCHANGE ACT OF 1934**





For
      the
      transition period from ________to _______





Commission
      file number 333-119328-03




LB-UBS
        Commercial Mortgage Trust 2005-C1,
 Commercial
        Mortgage Pass-Through Certificates, Series 2005-C1
 (Name
        of
        the issuing entity)


Structured
      Asset Securities Corporation II


(Exact
      name of registrant as specified in its charter)





Delaware
            
            82-0569805(State
                or other jurisdiction of
              incorporation
                or organization)
            
            (I.R.S.
                Employer
              Identification
                No.)





745
      Seventh Avenue, New York, New York 10019


(Address
      of principal executive offices)





Registrant’s
      telephone number, including area code: 212-526-7000





Securities
      registered pursuant to Section 12(b) of the Act: None





Securities
      registered pursuant to Section 12(g) of the Act: None


Lehman
        Brothers Holding Inc.
 (Name
        of
        the sponsor as specific in its charter)


Indicate
      by check mark if the registrant is a well-known seasoned issuer, as defined
      in
      Rule 405 of the Securities Act.





oYes
            
            xNo





Indicate
      by check mark if the registrant is not required to file pursuant to Section
      13
      or Section 15(d) of the Act.





oYes
            
            xNo





Indicate
      by check mark whether the 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.





xYes
            
            oNo





Indicate
      by check mark if disclosure of delinquent filers pursuant to Item 405 of
      Regulation S K (~229.405 of this chapter) is not contained herein, and will
      not
      be contained, to the best of registrant’s knowledge, in definitive proxy or
      information statements incorporated by reference in Part III of this Form 10-K
      or any amendment to this Form 10-K.





Not
      Applicable





Indicate
      by check mark whether the registrant is a large accelerated filer, an
      accelerated filer, or a non-accelerated filer. See definition of “accelerated
      filer and large accelerated filer” in Rule 12b-2 of the Exchange Act (Check
      one):





Large
                accelerated filero
            
            
            Accelerated
                filero
            
            
            Non-accelerated
                filerx








Indicate
      by check mark whether the registrant is a shell company (as defined in Rule
      12b-2 of the Act).





oYes
            
            xNo








State
      the
      aggregate market value of the voting and non voting common equity held by
      non-affiliates computed by reference to the price at which the common equity
      was
      last sold, or the average bid and asked price of such common equity, as of
      the
      last business day of the registrant’s most recently completed second fiscal
      quarter.





Not
      Applicable








DOCUMENTS
      INCORPORATED BY REFERENCE





Not
      Applicable




This
        Annual Report on Form 10-K (the “Report”) is filed with respect to the trust
        fund entitled LB-UBS Commercial Mortgage Trust 2005-C1 (the “Trust ”) formed
        pursuant to the pooling and servicing agreement dated as of January 11, 2005
        (the “Pooling and Servicing Agreement”) among Structured Asset Securities
        Corporation II, as depositor (the “Depositor”), Wachovia Bank, National
        Association, as master servicer (the “Master Servicer”), CWCapital Asset
        Management LLC (as successor in interest to Allied
        Capital Corporation) as special servicer (the
“Special Servicer”), LaSalle Bank National Association, as trustee (the
“Trustee”) and ABN AMRO Bank N.V., as fiscal agent, for the issuance of LB-UBS
        Commercial Mortgage Trust 2005-C1, Commercial Mortgage Pass-Through
        Certificates, Series 2005-C1 (the “Certificates”).





**PART
      I**





**Item
      1. Business.**





Not
      applicable.





**Item
      1A. Risk Factors.**





Not
      applicable.





**Item
      1B. Unresolved Staff Comments.**





None.





**Item
      2. Properties.**





Information
      with respect to the servicing of the mortgage loans and mortgaged properties
      is
      provided by reference to the Annual Independent Accountants' Report
      attached as Exhibit 99.1 and to the Annual Statement of Compliance attached
      as
      Exhibit 99.3.





**Item
      3. Legal Proceedings.**





The
      registrant knows of no material pending legal proceedings involving the trust
      created under the Pooling and Servicing Agreement for the Trust, the
      Trustee, the Master Servicer or the registrant with respect to the Trust other
      than routine litigation incidental to the duties of the respective
      parties.





**Item
      4. Submission of Matters to a Vote of Security Holders.**





None.








**PART
      II**





**Item
      5. Market for Registrant’s Common Equity, Related Stockholder Matters and Issuer
      Purchases of Equity Securities.**


Currently,
        there is no established trading market for the Certificates known to the
        Registrant.




Records
        provided to the Trust by the DTC and the Trustee indicate that as of December
        31, 2005, the total number of holders of record for the Series of Certificates
        is 108.
  **Item
      6. Selected Financial Data.**





Not
      applicable.





**Item
      7. Management’s Discussion and Analysis of Financial Condition and Results of
      Operation.**





Not
      applicable.





**Item
      7A. Quantitative and Qualitative Disclosures About Market
      Risk.**





Not
      applicable.





**Item
      8. Financial Statements and Supplementary Data.**





Not
      applicable.





**Item
      9. Changes in and Disagreements With Accountants on Accounting and Financial
      Disclosure.**





None.





**Item
      9A. Controls and Procedures.**





Not
      applicable.





**Item
      9B. Other Information.**





None.








**PART
      III**





**Item
      10. Directors and Executive Officers of the Registrant.**





Not
      applicable.





**Item
      11. Executive Compensation.**





Not
      applicable.





**Item
      12. Security Ownership of Certain Beneficial Owners and Management and Related
      Stockholder Matters.**





The
        current Controlling Class is Class S. The Controlling Class Representative
        was Allied Capital Corporation through July 13, 2005 and CWCapital Asset
        Management LLC from July 14, 2005 through December 31, 2005.





**Item
      13. Certain Relationships and Related Transactions.**





None.





**Item
      14. Principal Accounting Fees and Services.**





Not
      applicable.








**PART
      IV**








**Item
      15. Exhibits, Financial Statement Schedules.**





(a) (1)
        Not
        Applicable
  (2)
        Not
        Applicable
  (3)
        The
        exhibits required to be filed by Registrant pursuant to Item 601 of Regulation
        S-K are as follows :




**Exhibit
                Number**
            **Description**3
            Pooling
              and Servicing Agreement (Filed as part of the Registrant’s Current Report
              on Form 8-K filed on February 25, 2005)4
            Pooling
              and Servicing Agreement (Filed as part of the Registrant’s Current Report
              on Form 8-K filed on February 25, 2005)31
            Sarbanes-Oxley
                Certification99.1(a)
            Annual
                Independent Accountants’ Report, Wachovia Bank, National Association, as
                Master Servicer99.1(b)
            Annual
                Independent Accountants’ Report, Allied Capital Corporation, as Special
                Servicer99.1(c)
            Annual
                Independent Accountants’ Report, CWCapital Asset Management LLC, as
                successor Special Servicer99.2(a)
            Annual
                Report of Management, Wachovia Bank, National Association, as Master
                Servicer99.2(b)
            Annual
                Report of Management, Allied Capital Corporation, as Special
                Servicer99.2(c)
            Annual
                Report of Management, CWCapital Asset Management LLC, as successor
                Special
                Servicer99.3(a)
            Annual
                Statement of Compliance, Wachovia Bank, National Association, as
                Master
                Servicer99.3(b)
            Annual
                Statement of Compliance, Allied Capital Corporation, as Special
                Servicer99.3(c)
            Annual
                Statement of Compliance, CWCapital Asset Management LLC, as successor
                Special Servicer99.4
            Aggregate
                Statement of Principal and Interest Distributions to Certificateholders
                as
                of December 31, 2005


(b)
See
        subparagraph (a)(3) above.
  (c) Not
        applicable.










**SIGNATURES**





Pursuant
      to the requirements of Section 13 or 15(d) 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.





Structured
        Asset Securities Corporation II as Depositor for LB-UBS Commercial Mortgage
        Trust 2005-C1,Commercial
        Mortgage Pass-Through Certificates, Series 2005-C1
 (Registrant)


By:  /s/
      Ken Cohen


Name:
      Ken
      Cohen


Title:
      Managing Director






By:  /s/
      Paul Hughson


Name:
      Paul Hughson


Title:
      Managing Director





Date:
      March 29, 2006







SUPPLEMENTAL
      INFORMATION TO BE FURNISHED WITH REPORTS FILED PURSUANT TO SECTION 15(d) OF
      THE
      ACT BY REGISTRANTS WHICH HAVE NOT REGISTERED SECURITIES PURSUANT TO SECTION
      12
      OF THE ACT.




(a)
      (i)
      No annual report is provided to the Certificateholders other than with respect
      to aggregate principal and interest distributions attached as Exhibit
      99.4.




(a)
      (ii)
      No proxy statement, form of proxy or other proxy soliciting material has been
      sent to any Certificateholder with respect to any annual or other meeting of
      Certificateholders.













**EXHIBIT
      INDEX**


**Exhibit
                Number**
            **Description**3
            Pooling
              and Servicing Agreement (Filed as part of the Registrant’s Current Report
              on Form 8-K filed on February 25, 2005)*4
            Pooling
              and Servicing Agreement (Filed as part of the Registrant’s Current Report
              on Form 8-K filed on February 25, 2005)*31
            Sarbanes-Oxley
                Certification99.1(a)
            Annual
                Independent Accountants’ Report, Wachovia Bank, National Association, as
                Master Servicer99.1(b)
            Annual
                Independent Accountants’ Report, Allied Capital Corporation, as Special
                Servicer99.1(c)
            Annual
                Independent Accountants’ Report, CWCapital Asset Management LLC, as
                successor Special Servicer99.2(a)
            Annual
                Report of Management, Wachovia Bank, National Association, as Master
                Servicer99.2(b)
            Annual
                Report of Management, Allied Capital Corporation, as Special
                Servicer99.2(c)
            Annual
                Report of Management, CWCapital Asset Management LLC, as successor
                Special
                Servicer99.3(a)
            Annual
                Statement of Compliance, Wachovia Bank, National Association, as
                Master
                Servicer99.3(b)
            Annual
                Statement of Compliance, Allied Capital Corporation, as Special
                Servicer99.3(c)
            Annual
                Statement of Compliance, CWCapital Asset Management LLC, as successor
                Special Servicer99.4
            Aggregate
                Statement of Principal and Interest Distributions to Certificateholders
                as
                of December 31, 2005