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

[ ]     TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES ACT
        OF 1934 For the transition period to ______ from _______


 Commission File Number  333-117232-21

                       GMACM MORTGAGE LOAN TRUST 2005-AR1
                                (Issuing Entity)

                    RESIDENTIAL ASSET MORTGAGE PRODUCTS, INC.
                                  (Depositor)
             (Exact name of registrant as specified in its charter)

        Delaware                                      41-1955181
State or other jurisdiction                       (I.R.S. Employer
incorporation or organization                     Identification No.)

  8400 Normandale Lake Blvd., Suite 250
         Minneapolis, Minnesota                            55437
(Address of Principal Executive Office)                  (Zip Code)

       Registrant's telephone number, including area code : (952) 857-7000


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

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

Indicate by check mark if the registrant is a well-known seasoned issuer, as
defined in Rule 405 of the Securities Act.  Yes [ ]  No [X]

Indicate by check mark if the registrant is not required to file reports
pursuant to Section 13 or Section 15(d) of the Act.  Yes [X]   No [ ]

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. Yes [X] No [ ]

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. [X]

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 12-b-2 of the Exchange Act.

Large accelerated filer [ ]   Accelerated filer [ ]   Non-accelerated filer [X]

Indicate by check mark whether the  registrant is a shell company (as defined in
Rule 12b-2 of the Exchange Act).    Yes [ ]   No [X]

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.        Registrant does not have any voting or non-voting common equity.

Documents Incorporated by Reference:  None


<PAGE>


PART I

Item 1.  Business.

         Not Applicable.

Item 1A. Risk Factors.

         Not Applicable.

Item 1B. Unresolved Staff Comments.

         Not Applicable.

Item 2.  Properties.

         Not Applicable.

Item 3.  Legal Proceedings.

         The registrant is not aware of any material legal proceeding with
         respect to the company, the servicer or the trustee, as related to
         the trust.

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

         No matter was submitted to a vote or consent of Holders of the Offered
         Certificates during the fiscal year covered by this report.

PART II

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

         The  Trust  does  not issue stock.  There is  currently no  established
         public  trading  for the  Certificates. As  of December 31,  2005,  the
         number of holders of all classes of Notes was 30.

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

         There  was  no change of accountants or  disagreement with  accountants
         on  any  matter of  accounting  principles or  practices  or  financial
         disclosure.

Item 9A. Controls and Procedures.

         Not Applicable.

Item 9B. Other Information.

         Not Applicable.

                                      -2-

<PAGE>

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.

         Not Applicable.

Item 13. Certain Relationships and Related Transactions.

         Not Applicable.

Item 14. Principal Accounting Fees and Services.

         Not Applicable.

PART IV

Item 15. Exhibits, Financial Statement Schedules.

(a)      Exhibit 31.1   Rule 13a-14(a)/15d-14(a) Certification

         Exhibit 99.1   Annual Independent Accountants' Servicing Reports
                        concerning servicing activities

         Exhibit 99.2   Report of Management as to Compliance with Minimum
                        Servicing Standards

         Exhibit 99.3   Annual Statements of Compliance under the Pooling and
                        Servicing Agreements

         Exhibit 99.4   Aggregate Statement of Principal and Interest
                        Distributions to Certificate Holders
(b)      Not Applicable.

(c)      Not Applicable.
                                      -3-

<PAGE>



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,  there  unto duly  authorized,  on this 20th day of
March, 2006.

        By:  GMAC MORTGAGE CORPORATION, as Servicer

        By:  /s/ Anthony N. Renzi
             -------------------------
       Name: Anthony N. Renzi
      Title: Executive Vice President

       Date: March 20, 2006



                                      -4-
<PAGE>

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.

The  registrant  has not sent an annual report or proxy material to its security
holders.  The registrant  will not be sending an annual report or proxy material
to its security holders subsequent to the filing of this form.

                                      -5-
<PAGE>


                                 EXHIBIT INDEX

Exhibit     Description
-------     -----------

31.1        Rule 13a-14(a)/15d-14(a) Certification

99.1        Annual Independent Accountants' Servicing Reports concerning
            servicing activities

99.2        Report of Management as to Compliance with Minimum Servicing
            Standards

99.3        Annual Statements of Compliance under the Pooling and Servicing
            Agreements

99.4        Aggregate Statement of Principal and Interest Distributions to
            Certificate Holders


                                      -6-
<PAGE>

                                  Exhibit 31.1

                                 CERTIFICATION
                                ---------------

     I, Anthony N. Renzi, certify that:

1.   I have  reviewed  the annual  report on Form 10-K for the fiscal year ended
     December 31, 2005, and all reports on Form 8-K containing  distribution  or
     servicing  reports filed in respect of periods included in the year covered
     by this annual report, of GMACM Mortgage Loan Trust 2005-AR1.

2.   Based on my knowledge,  the information in these reports, taken as a whole,
     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 as of
     the last day of the period covered by that annual report;

3.   Based on my knowledge,  the distribution or servicing  information required
     to be  provided  to the  trustee  by the  servicer  under the  pooling  and
     servicing,  or  similar,  agreement,  for  inclusion  in these  reports  is
     included in these reports;

4.   I am  responsible  for reviewing the  activities  performed by the servicer
     under the pooling and  servicing,  or  similar,  agreement  and based on my
     knowledge and the annual  compliance  review required under that agreement,
     and except as  disclosed in the reports,  the  servicer has  fulfilled  its
     obligations  under  that  agreement; and

5.   The  reports  disclose  all  significant   deficiencies   relating  to  the
     servicer's  compliance with the minimum servicing  standards based upon the
     report provided by an independent  public  accountant , after  conducting a
     review in  compliance  with the  Uniform  Single  Attestation  Program  for
     Mortgage  Bankers,  or similar  procedure,  as set forth in the pooling and
     servicing,  or similar,  agreement,  that is included in these reports.

     In giving the certifications above, I have reasonably relied on information
provided to me by the following unaffiliated parties: JPMorgan Chase Bank, N.A.

 By:    GMAC MORTGAGE CORPORATION

 By:    /s/ Anthony N. Renzi
        ------------------------
 Name:  Anthony N. Renzi
 Title: Executive Vice President
 Date:  March 20, 2006


<PAGE>

                                  EXHIBIT 99.1
                Annual Independent Accountants' Servicing Reports
                        Concerning Servicing Activities
                         ------------------------------

                                                PricewaterhouseCoopers LLP
                                                PricewaterhouseCoopers Center
                                                300 Madison Avenue
                                                New York NY 10017
                                                Telephone (646) 741 3000
                                                Facsimile (813) 286 6000

                       Report of Independent Accountants

To the Board of Directors and Shareholder
of GMAC Mortgage Corporation:

We have examined management's  assertion about GMAC Mortgage Corporation and its
subsidiaries  (the "Company")  compliance with the minimum  servicing  standards
identified  in the Mortgage  Bankers  Association  of America's  Uniform  Single
Attestation  Program for Mortgage  Bankers ("USAP") as of and for the year ended
December 31, 2005 included in the accompanying management assertion (see Exhibit
I).  Management is responsible  for the Company's  compliance with those minimum
servicing standards. Our responsibility is to express an opinion on management's
assertion about the Company's compliance based on our examination.

Our  examination  was  performed  in  accordance  with   attestation   standards
established  by the  American  Institute of Certified  Public  Accountants  and,
accordingly,  included examining,  on a test basis, evidence about the Company's
compliance  with the  minimum  servicing  standards  and  performing  such other
procedures as we considered necessary in the circumstances.  We believe that our
examination  provides a reasonable  basis for our opinion.  Our examination does
not provide a legal  determination on the Company's  compliance with the minimum
servicing standards.

In our  opinion,  management's  assertion  that the  Company  complied  with the
aforementioned minimum servicing standards as of and for the year ended December
31, 2005 is fairly stated, in all material respects.


 /s/ PricewaterhouseCoopers, LLP
 --------------------------------
 PricewaterhouseCooper, LLP

 March 21, 2006


<PAGE>

                                  EXHIBIT 99.2
                   Report of Management as to Compliance with
                          Minimum Servicing Standards
                         ------------------------------


GMAC Mortgage
                                                                Exhibit I


                  Management's Assertion Concerning Compliance
                     with USAP Minimum Servicing Standards

March 21, 2006

As of and for the year ended December 31, 2005,  GMAC Mortgage  Corporation  and
its subsidiaries (the "Company") have complied in all material respects with the
minimum  servicing  standards set forth in the Mortgage  Bankers  Association of
America's Uniform Single Attestation Program for Mortgage Bankers ("USAP").

As of and for this same  period,  the Company had in effect a fidelity  bond and
errors and omissions  policies in the amounts of $350,000,000 and  $100,000,000,
respectively.


 /s/ Jim Hillsman
 -------------------
 Jim Hillsman
 Chief Operating Officer
 GMAC Residential Holding Corp

 /s/ Dave Bricker
 -------------------
 Dave Bricker
 Chief Financial Officer
 GMAC Residential Holding Corp

 /s/ Tony Renzi
 -------------------
 Tony Renzi
 Executive Vice President,
 National Servicing Administration
 GMAC Residential Holding Corp



<PAGE>


                                  EXHIBIT 99.3
                         Annual Statements of Compliance
                   under the Pooling and Servicing Agreements
                         -------------------------------

February 28, 2006

RESIDENTIAL ASSET MORTGAGE PRODUCTS
DIANE WALLACE
c/o JPMORGAN CHASE BANK
4 New York Plaza - 6th Floor
New York, NY  10004

RE:  Annual Officers Statement of Compliance
     Year Ending 2005
     GMACM Investor Agreement #41232, Deal 2005-AR1

GMAC Mortgage Corporation ("GMACM") hereby certifies to the best of our
knowledge and belief, that for the calendar year 2005:

1.   A  review  of the  activities  of the  Seller/Servicer  and of  performance
     according  to  the   Seller/Servicer   contract  has  been  made under such
     undersigned Officer's supervision.
2.   To the  best of the  undersigned  Officer's  knowledge,  and  based on such
     review, the  Seller/Servicer  has fulfilled all its  obligations  under the
     Guides for such year.
3.   GMACM is currently an approved FNMA and FHLMC Servicer in good standing.
4.   If applicable, GMACM has filed the information returns with respect to the
     receipt of mortgage interest pursuant to Sections 6050H, 5060J and 6050P of
     the Code,  received in a trade or  business,  reports of  foreclosures  and
     abandonment's  of  any  Mortgaged  Property  and  the  information  returns
     relating  to  cancellation  of  indebtedness  income  with  respect  to any
     Mortgaged Property.
4.   All hazard,  flood, FHA mortgage  insurance and primary mortgage  insurance
     premiums,  taxes,  ground rents,  assessments and other lienable items have
     been paid in connection with the mortgaged properties.
5.   All property inspections have been completed as required.
6.   Compliance relative to Adjustable Rate Mortgages has been met.
7.   Fidelity Bond and Errors and Omissions  Insurance  coverage is current,  in
     full force and effect.

Servicer:    GMAC Mortgage Corporation

By:          /s/ Michael Kacergis
             ------------------------
Name:        Michael Kacergis

Title:       Manager
             Enterprise Risk Management
             Enterprise Servicing Group Risk and Compliance

<PAGE>

                                  EXHIBIT 99.4
         Aggregate Statement of Principal and Interest Distributions to
                               Certificate Holders
                         -------------------------------

<TABLE>
<S>     <C>    <C>    <C>    <C>    <C>    <C>
-----------------------------------------------------------------------------------------------------------------------------------
                                  DISTRIBUTION IN DOLLARS
-----------------------------------------------------------------------------------------------------------------------------------
CUSIP        ORIGINAL PRIN       PAID PRIN          PAID INT          TOTAL PAID     ENDING PRIN BALANCE    CERT POOL FACTOR
-----------------------------------------------------------------------------------------------------------------------------------
76112BKK5   12,000,000.00          26,253.10         5,203.16          31,456.26        11,973,746.90          997.81224167
76112BKL3   34,000,000.00          74,383.79        14,742.26          89,126.05        33,925,616.21          997.81224147
76112BKY5    1,615,000.00           3,533.23           700.26           4,233.49         1,611,466.77          997.81224149
76112BKM1   81,923,000.00         165,603.54        39,825.17         205,428.71        81,757,396.46          997.97854644
76112BKN9  156,115,000.00         271,092.15        72,728.19         343,820.34       155,843,907.85          998.26350991
76112BKP4   21,512,000.00          26,835.42        10,400.13          37,235.55        21,485,164.58          998.75253719
76112BKS8    7,796,000.00             214.70         4,071.31           4,286.01         7,795,785.30          999.97246024
76112BKT6    3,198,000.00              88.07         1,670.10           1,758.17         3,197,911.93          999.97246091
76112BKU3    1,999,000.00              55.05         1,043.93           1,098.98         1,998,944.95          999.97246123
76112BKQ2   75,612,000.00          93,784.34        40,339.40         134,123.74        75,518,215.66          998.75966328
76112BKR0               -                  -             1.01               1.01                    -        1,000.00000000
76112BKV1    1,993,993.39              49.52           939.50             989.02         1,993,943.87          999.97516541
76112BKW9    1,399,000.00              38.52           730.60             769.12         1,398,961.48          999.97246605
76112BKX7      799,723.00              22.02           417.66             439.68           799,700.98          999.97246547
-----------------------------------------------------------------------------------------------------------------------------------
</table>