Registration Statement No. 333-143354

811-09137

As Filed with the Securities and Exchange Commission on October 7, 2008

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM N-6

REGISTRATION UNDER THE SECURITIES ACT OF 1933          [ X ]

Pre-Effective Amendment No.          [  ]

Post-Effective Amendment No.   4           [ X ]

and/or

REGISTRATION STATEMENT UNDER THE INVESTMENT COMPANY ACT OF 1940         [ X ]

Amendment No.   66           [ X ]

Sun Life of Canada (U.S.) Variable Account I

Registrant

Sun Life Assurance Company of Canada (U.S.)

Depositor

One Sun Life Executive Park

Wellesley Hills, Massachusetts 02481

Depositor's Address

1-800-700-6554

Depositor's Telephone Number

Sandra DaDalt

Assistant Vice President and Senior Counsel

Sun Life Assurance Company of Canada (U.S.)

One Sun Life Executive Park

Wellesley Hills, Massachusetts 02481

Name and Address of Agent For Service

It is proposed that this filing will become effective (check appropriate box)

[  ]  immediately upon filing pursuant to paragraph (b) of Rule 485.

[  ]  on October 6, 2008 pursuant to paragraph (b) of Rule 485.

[ X ]  60 days after filing pursuant to paragraph (a)(1) of Rule 485.

[  ]  on November 1, 2008 pursuant to paragraph (a)(1) of Rule 485.

[  ]  This post-effective amendment designates a new effective date for a previously filed post-effective amendment.

This Amendment No. 4 to the Registration Statement on Form N-6 (the "Registration Statement") (File Nos. 333-143354, 811-09137) is being filed pursuant to Rule 485(a) under the Securities Act of 1933, as amended, in order to add a supplement to the prospectus filed with Post-Effective Amendment No. 2 on April 24, 2008. This Amendment does not otherwise delete, amend, or supersede any prospectus, statement of additional information, exhibit, or other information contained in Post-Effective Amendment Nos. 2 and 3.

PART A

SUPPLEMENT DATED DECEMBER 7, 2008

TO

PROSPECTUS DATED MAY 1, 2008

FOR

SUN PRIME VARIABLE UNIVERSAL LIFE

ISSUED BY SUN LIFE ASSURANCE COMPANY OF CANADA (U.S.)

SUN LIFE OF CANADA (U.S.) VARIABLE ACCOUNT I

For Policies with an Investment Start Date on or after January 28, 2009, and if approved by your state insurance regulator, the following description of the Supplemental Insurance Rider replaces the Supplemental Insurance Rider description in the prospectus:

Supplemental Insurance Rider.  This rider provides for additional insurance on the life of the Insured by combining term coverage with the underlying variable universal life ("base policy") coverage.  The rider charge covers the cost of insurance charges we incur for the insurance coverage provided by this rider.  Those cost of insurance charges are generally lower than the cost of insurance charges that apply to insurance coverage under the base policy, as are our selling costs, including commissions.

By combining coverage under this rider with base policy coverage, You may be able to buy the same amount of death benefit for less premium than if You had purchased an all base policy.  If this rider is combined with base policy coverage, the same amount of premium paid for the combined coverage as for an all base policy will generate faster cash value accumulation within the base policy.  Additional underwriting requirements may be imposed at the time of rider election, which may occur after issue.

You may choose to schedule automatic increases in the Supplemental Insurance Rider Face Amount.  Evidence of insurability must be provided at the same time scheduled automatic increases are elected.  The amounts of scheduled increases and the dates those increases take effect are shown in the Policy Specifications section of the Policy.

You must have elected death benefit option A to have this rider and elect scheduled increases.  If You have elected scheduled increases and change from death benefit option A, future scheduled increases will be cancelled.  If You elect a decrease in the Specified Face Amount or the Supplemental Insurance Rider Face Amount, future scheduled increases will be cancelled.

If You elected a No-Lapse Guarantee, that No-Lapse Guarantee will apply to this rider for five years and not for the No-Lapse Guarantee Period on the base policy, if longer.  This rider will terminate at the policy anniversary on which the Insured reaches Attained Age 121.  Base policy coverage will continue beyond Attained Age 121 provided there is cash value in the Policy when the Insured reaches Attained Age 121.  If a key objective is application of the No-Lapse Guarantee to insurance coverage under both the base Policy and this rider for a long period of time, supplementing the Policy with this rider may therefore not be appropriate.

The Cost of Insurance rates used to determine the monthly rider charge deduction from the Account Value are based on the length of time the rider has been in force and the Insured's sex (in the case of non-unisex Policies), Issue Age and rating class.  The rates will be determined by us from time to time based on our expectations of future experience with respect to mortality costs, persistency, interest rates, expenses and taxes.  The rates for the rider will not exceed the Guaranteed Maximum Monthly Cost of Insurance Rates based on the 2001 Commissioner's Standard Ordinary Smoker and Nonsmoker Mortality Tables.  The rates for the rider if the LTA Rider also attaches to the Policy will not exceed the Guaranteed Maximum Monthly Cost of Insurance Rates based on the 2001 Commissioner's Standard Ordinary Aggregate Mortality Tables.  The 2001 Commissioner's Standard Ordinary Aggregate Mortality Tables blend smoker and nonsmoker mortality and are generally higher than the rates under the 2001 Commissioner's Standard Ordinary Smoker and Nonsmoker Mortality Tables.  The 2001 Commissioner's Standard Ordinary Aggregate Mortality Tables permit greater Policy funding without violating the Guideline Premium Test so a policyowner who wishes to heavily fund their Policy, as with the LTA Rider, would prefer application of these Tables.

You may discontinue this rider upon written request to the Company.  If discontinued, the rider charge will cease.

THIS SUPPLEMENT SHOULD BE READ AND RETAINED FOR FUTURE REFERENCE.

PART B

The Statement of Additional Information is incorporated herein by reference to Post-Effective Amendment No. 3 to the Registration Statement of Sun Life of Canada (U.S.) Variable Account I on Form N-6, File No. 333-143354, filed with the Securities and Exchange Commission on September 16, 2008.

PART C

ITEM 26.  EXHIBITS

A. Resolution of the Board of Directors of Sun Life Assurance Company of Canada (U.S.), dated October 29, 1998, authorizing the establishment of Sun Life of Canada (U.S.) Variable Account I (Incorporated herein by reference to the Registration Statement of Sun Life of Canada (U.S.) Variable Account I on Form S-6, File No. 333-68601, filed with the Securities and Exchange Commission on December 9, 1998.)

B. None.

C. Principal Underwriting Agreement (Incorporated herein by reference to Post-Effective Amendment No. 2 to the Registration Statement of Sun Life of Canada (U.S.) Variable Account I on Form S-6, File No. 333-94359, filed with the Securities and Exchange Commission on March 31, 2000.)

D. (1)  Flexible Premium Combination Fixed and Variable Life Insurance Policy.  (Incorporated herein by reference to the Registration Statement of Sun Life of Canada (U.S.) Variable Account I on Form N-6, File No. 333-143354, filed with the Securities and Exchange Commission on May 30, 2007.)

(2)  Accelerated Death Benefit Rider (Incorporated herein by reference to Pre-Effective Amendment No. 1 to the Registration Statement of Sun Life of Canada (U.S.) Variable Account I on Form S-6, File No. 333-68601, filed with the Securities and Exchange Commission on April 27, 1999.)

(3)  Payment of Stipulated Premium Rider (Incorporated herein by reference to Pre-Effective Amendment No. 1 to the Registration Statement of Sun Life of Canada (U.S.) Variable Account I on Form S-6, File No. 333-68601, filed with the Securities and Exchange Commission on April 27, 1999.)

(4)  Waiver of Monthly Deductions (Incorporated herein by reference to Pre-Effective Amendment No. 2 to the Registration Statement of Sun Life of Canada (U.S.) Variable Account I on Form N-6, File No. 333-143353, filed with the Securities and Exchange Commission on September 19, 2007.)

(5)  Supplemental Insurance Rider (Incorporated herein by reference to Post-Effective Amendment No. 4 to the Registration Statement of Sun Life of Canada (U.S.) Variable Account I on Form S-6, File No. 333-68601, filed with the Securities and Exchange Commission on February 12, 2001.)

(6)  Charitable Giving Benefit Rider.  (Incorporated herein by reference to Pre-Effective Amendment No. 2 to the Registration Statement of Sun Life of Canada (U.S.) Variable Account I on Form N-6, File No. 333-143353, filed with the Securities and Exchange Commission on September 19, 2007.)

(7)  Enhanced Cash Surrender Value Rider. (Incorporated herein by reference to the Registration Statement of Sun Life of Canada (U.S.) Variable Account I on Form N-6, File No. 333-143354, filed with the Securities and Exchange Commission on May 30, 2007.)

(8)  Loan Lapse Protection Rider. (Incorporated herein by reference to the Registration Statement of Sun Life of Canada (U.S.) Variable Account I on Form N-6, File No. 333-143354, filed with the Securities and Exchange Commission on May 30, 2007.)

(9)  Long Term Accumulation Rider. (Incorporated herein by reference to the Registration Statement of Sun Life of Canada (U.S.) Variable Account I on Form N-6, File No. 333-143354, filed with the Securities and Exchange Commission on May 30, 2007.)

(10) Travel Assistance Endorsement. (Incorporated herein by reference to Pre-Effective Amendment No. 2 to the Registration Statement of Sun Life of Canada (U.S.) Variable Account I on Form N-6, File No. 333-143353, filed with the Securities and Exchange Commission on September 19, 2007.)

(11)  Supplemental Insurance Rider.

E. Application for Flexible Premium Combination Fixed and Variable Life Insurance Policy. (Incorporated herein by reference to the Registration Statement of Sun Life of Canada (U.S.) Variable Account I on Form N-6, File No. 333-143354, filed with the Securities and Exchange Commission on May 30, 2007.)

F. (1)  Certificate of Incorporation of Sun Life Assurance Company of Canada (U.S.) (Incorporated herein by reference to the Depositor's Form 10-K, File No. 333-82824, filed with the Securities and Exchange Commission on March 29, 2004.)

(2)  Bylaws of the Depositor, as amended March 19, 2004 (Incorporated herein by reference to the Depositor's Form 10-K, File No. 333-82824, filed with the Securities and Exchange Commission on March 29, 2004.)

G. Specimen Reinsurance Contract. (Incorporated herein by reference to the Registration Statement of Sun Life of Canada (U.S.) Variable Account I on Form N-6, File No. 333-100829, filed with the Securities and Exchange Commission on October 30, 2002.)

H.           (1)      Participation Agreement, dated February 17, 1998, by and among AIM Variable Insurance Funds, Inc., AIM Distributors, Inc., Sun Life Assurance Company of Canada (U.S.), and Clarendon Insurance Agency, Inc. (Incorporated herein by reference to Post-Effective Amendment No. 1 to the Registration Statement of Sun Life of Canada (U.S.) Variable Account F on Form N-4, Exhibit 8d, File No. 333-82957, filed with the Securities and Exchange Commission on February 3, 2000.)

(2)      Amended and Restated Participation Agreement, dated December 13, 2004, by and among Sun Capital Advisers Trust, Sun Capital Advisers, Inc., Sun Life Insurance and Annuity Company of New York and Sun Life Assurance Company of Canada (U.S.) (Incorporated herein by reference to Post-Effective Amendment No. 8 to the Registration Statement of Sun Life of Canada (U.S.) Variable Account F on Form N-4, Exhibit 8e, File No. 333-83516, filed with the Securities and Exchange Commission on April 29, 2005.)

(3)      Amended and Restated Participation Agreement, dated September 1, 2004, by and among Sun Life Assurance Company of Canada (U.S.), Variable Insurance Products Fund and Fidelity Distributors Corporation (Incorporated herein by reference to Post-Effective Amendment No. 8 to the Registration Statement of Sun Life of Canada (U.S.) Variable Account F on Form N-4, Exhibit 8g, File No. 333-83516, filed with the Securities and Exchange Commission on April 28, 2005.)

(4)      Participation Agreement, dated May 1, 2001, by and among Sun Life Assurance Company of Canada (U.S.), Clarendon Insurance Agency, Inc., Alliance Capital Management L.P. and Alliance Fund Distributors, Inc. (Incorporated herein by reference to Post-Effective Amendment No. 10 to the Registration Statement of Sun Life of Canada (U.S.) Variable Account F on Form N-4, Exhibit 8k, File No. 333-82957, filed with the Securities and Exchange Commission on April 23, 2004.)

(5)      Participation Agreement, dated September 16, 2002, by and among the Franklin Templeton Variable Insurance Products Trust, Franklin Templeton Distributors, Inc, Sun Life Insurance and Annuity Company of New York and Sun Life Assurance Company of Canada (U.S.) (Incorporated herein by reference to the Registration Statement of KBL Variable Account A on Form N-4, Exhibit 8g, File No. 333-102278, filed with the Securities and Exchange Commission on December 31, 2002.)

(6)      Participation Agreement, dated February 17, 1998, by and among Goldman Sachs Variable Insurance Trust, Goldman, Sachs & Co., and Sun Life Assurance Company of Canada (U.S.) (Incorporated herein by reference to Post-Effective Amendment No. 13 to the Registration Statement of Sun Life of Canada (U.S.) Variable Account F on Form N-4, Exhibit 8b, File No. 033-41628, filed with the Securities and Exchange Commission on April 26, 1999.)

(7)      Amended and Restated Participation Agreement, dated November 6, 2002, by and among MFS/Sun Life Series Trust, Sun Life Insurance and Annuity Company of New York, Sun Life Assurance Company of Canada (U.S.) and Massachusetts Financial Services Company (Incorporated herein by reference to Post-Effective Amendment No. 3 to the Registration Statement of Sun Life (N.Y.) Variable Account C on Form N-4, Exhibit 8a, File No. 333-107983, filed with the Securities and Exchange Commission on May 28, 2004.)

(8)      Participation Agreement, dated July 15, 2002, by and among Sun Life Assurance Company of Canada (U.S.), Deutsche Asset Management VIT Funds and Deutsche Asset Management, Inc. (Incorporated herein by reference to Post-Effective Amendment No. 2 to the Registration Statement of Sun Life of Canada (U.S.) Variable Account G on Form S-6, Exhibit 8o, File No. 333-65048, filed with the Securities and Exchange Commission on July 3, 2002.)

(9)      Participation Agreement, dated September 30, 2002, by and among Sun Life Assurance Company of Canada (U.S.), Sun Life Insurance and Annuity Company of New York, First Eagle Sogen Variable Funds, Inc. and Arnhold and S. Bleichroeder, Inc. (Incorporated herein by reference to the Registration Statement of Sun Life of Canada (U.S.) Variable Account I on Form N-6, File No. 333-143354, filed with the Securities and Exchange Commission on May 30, 2007.)

(10) Participation Agreement, dated September 16, 2002, by and among Sun Life Assurance Company of Canada (U.S.), Sun Life Insurance and Annuity Company of New York, PIMCO Variable Insurance Trust and PIMCO Funds Distributors LLC. (Incorporated herein by reference to Post-Effective Amendment No. 3 to the Registration Statement of Sun Life of Canada (U.S.) Variable Account I on Form N-6, Exhibit H10, File No. 333-59662, filed with the Securities and Exchange Commission on February 26, 2003.)

(11)    Participation Agreement, dated December 1, 2004, by and among Wanger Advisors Trust, Columbia Funds Distributor, Inc., Sun Life Assurance Company of Canada (U.S.) and Sun Life Insurance and Annuity Company of New York.  (Incorporated herein by reference to the Registration Statement of Sun Life (N.Y.) Variable Account J on Form N-6, Exhibit H20, File No. 333-136435, filed with the Securities and Exchange Commission on August 9, 2006.)

(12) Participation Agreement, dated February 17, 1998, by and among Sun Life Assurance Company of Canada (U.S.) and Lord, Abbett & Co. (Incorporated herein by reference to Post-Effective Amendment No. 8 to the Registration Statement of Sun Life of Canada (U.S.) Variable Account G on Form S-6, Exhibit 8i, File No. 333-13087, filed with the Securities and Exchange Commission on April 26, 2002.)

(13) Participation Agreement, dated August 6, 2004, by and among Sun Life Assurance Company of Canada (U.S.), Van Kampen Life Investments Trust, Van Kampen Funds Inc., Van Kampen Asset Management. (Incorporated herein by reference to Post-Effective Amendment No. 4 to the Registration Statement of Sun Life of Canada (U.S.) Variable Account I on Form N-6, Exhibit H16, File No. 333-100831, filed with the Securities and Exchange Commission on April 29, 2005).

(14) Participation Agreement, dated December 31, 2002, by and among Oppenheimer Variable Account Funds, OppenheimerFunds, Inc. and Sun Life Assurance Company of Canada (U.S.). (Incorporated herein by reference to Post-Effective Amendment No. 4 to the Registration Statement of Sun Life of Canada (U.S.) Variable Account I on Form N-6, Exhibit H17, File No. 333-100831, filed with the Securities and Exchange Commission on April 29, 2005).

(15)   Restated Participation Agreement, dated April 1, 2007, by and among Sun Life Assurance Company of Canada (U.S.), Sun Life Insurance and Annuity Company of New York, Independence Life and Annuity Company, Columbia Funds Variable Insurance Trust I, Columbia Management Advisors, LLC and Columbia Management Distributors, Inc. (Incorporated herein by reference to the Registration Statement of Sun Life of Canada (U.S.) Variable Account I on Form N-6, Exhibit H15, File No. 333-143353, filed with the Securities and Exchange Commission on May 30, 2007.)

(16)   Participation Agreement, dated April 1, 2007, by and among Sun Life Assurance Company of Canada (U.S.), M Fund, Inc., M Financial Investment Advisers, Inc. and Sun Life Insurance and Annuity Company of New York. (Incorporated herein by reference to the Registration Statement of Sun Life of Canada (U.S.) Variable Account I on Form N-6, File No. 333-143354, filed with the Securities and Exchange Commission on May 30, 2007.)

(17)   Participation Agreement, dated May 13, 2004, by and among Sun Life Assurance Company of Canada (U.S.), Merrill Lynch Variable Series Funds, Inc., Merrill Lynch Investment Managers, L.P. and FAM Distributors, Inc. (Incorporated herein by reference to Post-Effective Amendment No. 2 to the Registration Statement of Sun Life of Canada (U.S.) Variable Account G on Form N-6, File No. 333-111688, filed with the Securities and Exchange Commission on December 30, 2005.)

I. Third Party Administration Agreement between Sun Life Assurance Company of Canada (U.S.) and McCamish Systems, LLC.  (Incorporated herein by reference to Pre-Effective Amendment No. 2 to the Registration Statement of Sun Life of Canada (U.S.) Variable Account I on Form N-6, File No. 333-143354, filed with the Securities and Exchange Commission on October 10, 2007.)

J.            (1) Powers of Attorney. (Incorporated herein by reference to Post-Effective Amendment No. 2 to the Registration Statement of Sun Life of Canada (U.S.) Variable Account I on Form N-6, File No. 333-143354, filed with the Securities and Exchange Commission on April 24, 2008.)

(2)           Resolution of the Board of Directors of the Depositor dated July 24, 2003, authorizing the use of Powers of Attorney for Officer signatures. (Incorporated herein by reference to the Registration Statement of Keyport Variable Account A on Form N-4, File No. 333-112506, filed with the Securities and Exchange Commission on February 5, 2004.)

K.           Legal Opinion.

L.           None.

M.           None.

N.           Consent of Independent Registered Public Accounting Firm.

O.           None.

P.           None.

Q.           None.

ITEM 27.  DIRECTORS AND OFFICERS OF THE DEPOSITOR

Name and Principal Business Address	Positions and Offices With Depositor
Thomas A. Bogart Sun Life Assurance Company of Canada 150 King Street West Toronto, ON  M5H 1J9	Director and Chairman
Ronald H. Friesen Sun Life Assurance Company of Canada (U.S.) One Sun Life Executive Park Wellesley Hills, MA  02481	Director and Senior Vice President and Chief Financial Officer and Treasurer
Scott M. Davis Sun Life Assurance Company of Canada (U.S.) One Sun Life Executive Park Wellesley Hills, MA  02481	Director and Senior Vice President and General Counsel
Richard P. McKenney Sun Life Assurance Company of Canada 150 King Street West Toronto, Ontario Canada M5H 1J9	Director
Janet Whitehouse Sun Life Assurance Company of Canada (U.S.) One Sun Life Executive Park Wellesley Hills, MA  02481	Senior Vice President and General Manager, Employee Benefits Group
Robert C. Salipante Sun Life Assurance Company of Canada (U.S.) One Sun Life Executive Park Wellesley Hills, MA 02481	Director and President
Michele G. Van Leer Sun Life Assurance Company of Canada (U.S.) One Sun Life Executive Park Wellesley Hills, MA 02481	Senior Vice President and Director and General Manager, Retail Insurance and Annuity Division
James M.A. Anderson Sun Life Assurance Company of Canada 150 King Street West Toronto Ontario Canada  M5H 1J9	Executive Vice President and Chief Investment Officer
Keith Gubbay Sun Life Assurance Company of Canada  (U.S.) One Sun Life Executive Park Wellesley Hills, MA  02481	Senior Vice President and Chief Actuary
Michael S. Bloom Sun Life Assurance Company of Canada (U.S.) One Sun Life Executive Park Wellesley Hills, MA 02481	Assistant Vice President and Senior Counsel and Secretary
Maura E. Slattery Machold Sun Life Assurance Company of Canada (U.S.) One Sun Life Executive Park Wellesley Hills, MA 02481	Vice President, Human Resources and Chief Accounting Officer
John R. Wright Sun Life Assurance Company of Canada (U.S.) One Sun Life Executive Park Wellesley Hills, MA 02481	Executive Vice President, Sun Life Financial U.S. Operations
Michael E. Shunney Sun Life Assurance Company of Canada (U.S.) One Sun Life Executive Park Wellesley Hills, MA 02481	Senior Vice President and General Manager, Sun Life Financial Distribution Group

ITEM 28.  PERSONS CONTROLLED BY OR UNDER COMMON CONTROL WITH THE DEPOSITOR OR THE REGISTRANT

No person is directly or indirectly controlled by the Registrant.  The Registrant is a separate account of Sun Life Assurance Company of Canada (U.S.), which is ultimately controlled by Sun Life Financial.

The organization chart of Sun Life Financial is incorporated by reference to Post-Effective Amendment No. 25 to the Registration Statement on Form N-6 of Sun Life of Canada (U.S.) Variable Account F, File No. 333-83516, filed February 12, 2008.

None of the companies listed in such organization chart is a subsidiary of the Registrant; therefore, the only financial statements being filed are those of Sun Life Assurance Company of Canada (U.S.).

ITEM 29.  INDEMNIFICATION

Pursuant to Section 145 of the Delaware Corporation Law, Article 8 of the By-laws of Sun Life Assurance Company of Canada (U.S.) provides for the indemnification of directors, officers and employees of Sun Life Assurance Company of Canada (U.S.).  Insofar as indemnification for liability arising under the Securities Act of 1933 may be permitted to directors, officers and controlling persons of Sun Life Assurance Company of Canada (U.S.) pursuant to the certificate of incorporation, by-laws, or otherwise, Sun Life (U.S.) has been advised that in the opinion of the Securities and Exchange Commission such indemnification is against public policy as expressed in the Act and is, therefore, unenforceable.  In the event that a claim for indemnification against such liabilities (other than the payment by Sun Life (U.S.) of expenses incurred or paid by a director, officer, controlling person of Sun Life (U.S.) in the successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in connection with the securities being registered, Sun Life (U.S.) will submit to a court of appropriate jurisdiction the question whether such indemnification by them is against public policy as expressed in the Act, unless in the opinion of their counsel the matter has been settled by controlling precedent, and will be governed by the final adjudication of such issue.

ITEM 30.  PRINCIPAL UNDERWRITERS

(a)  Clarendon Insurance Agency, Inc., which is a wholly-owned subsidiary of Sun Life Assurance Company of Canada (U.S.), acts as general distributor for the Registrant, Sun Life of Canada (U.S.) Variable Accounts C, D, E, F, G and K, Keyport Variable Account A, KMA Variable Account, Keyport Variable Account I, KBL Variable Account A, KBL Variable Annuity Account, Sun Life (N.Y.) Variable Accounts A, B, C, D, J and N and Money Market Variable Account, High Yield Variable Account, Capital Appreciation Variable Account, Government Securities Variable Account, World Governments Variable Account and Total Return Variable Account.

(b)

Name and Principal	Position and Offices
Business Address*	with Underwriter
James J. Cahill	President
Scott M. Davis	Director
Michele G. Van Leer	Director
Ronald H. Friesen	Director
Ann B. Teixeira	Assistant Vice President, Compliance
Michael S. Bloom	Secretary
Kathleen T. Baron	Chief Compliance Officer
Michael L. Gentile	Vice President
William T. Evers	Assistant Vice President and Senior Counsel
Jane F. Jette	Financial/Operations Principal and Treasurer
Alyssa M. Gair	Assistant Secretary
Michelle D’Albero	Counsel

*The principal business address of all directors and officers of the principal underwriter is One Sun Life Executive Park, Wellesley Hills, Massachusetts 02481.

(c)  Not applicable.

ITEM 31.  LOCATION OF ACCOUNTS AND RECORDS

Accounts, books and other documents required to be maintained by Section 31(a) of the Investment Company Act of 1940 and the Rules promulgated thereunder are maintained, in whole or in part, by Sun Life Assurance Company of Canada (U.S.) at its offices at One Sun Life Executive Park, Wellesley Hills, Massachusetts 02481 or at the offices of Clarendon Insurance Agency, Inc., at One Sun Life Executive Park, Wellesley Hills, Massachusetts 02481.

ITEM 32.  MANAGEMENT SERVICES

Not applicable.

ITEM 33.  FEE REPRESENTATION

Sun Life Assurance Company of Canada (U.S.)("Sun Life of Canada (U.S.)") hereby represents that the aggregate fees and charges under the Policy are reasonable in relation to the services rendered, the expenses expected to be incurred, and the risks assumed by Sun Life (U.S.).

SIGNATURES

As required by the Securities Act of 1933 and the Investment Company Act of 1940, the Registrant has caused this Post-Effective Amendment to the Registration Statement to be signed on its behalf, in the Town of Wellesley Hills, and Commonwealth of Massachusetts on this 7th day of October, 2008.

SUN LIFE OF CANADA (U.S.) VARIABLE ACCOUNT I

(Registrant)

SUN LIFE ASSURANCE COMPANY OF CANADA (U.S.)

(Depositor)

By: ___/s/ Robert C. Salipante______________

Robert C. Salipante

President

Attest:	__/s/ Sandra M. DaDalt_________________
	Sandra M. DaDalt
	Assistant Vice President & Senior Counsel

As required by the Securities Act of 1933, this Registration Statement has been signed by the following persons in the capacities with the Depositor, Sun Life Assurance Company of Canada (U.S.), and on the dates indicated.

SIGNATURE	TITLE	DATE
/s/ Robert C. Salipante	Director and President	October 7, 2008
Robert C. Salipante	(Principal Executive Officer)
/s/ Ronald H. Friesen	Director and Senior Vice President and Chief Financial	October 7, 2008
Ronald H. Friesen	Officer and Treasurer
	(Principal Financial Officer)
/s/ Michael K. Moran	Vice President and Chief Accounting Officer	October 7, 2008
Michael K. Moran	(Principal Accounting Officer)
*By: /s/ Sandra M. DaDalt	Attorney-in-Fact for:	October 7, 2008
Sandra M. DaDalt
	Richard P. McKenney, Director
	Thomas A. Bogart, Director
	Scott M. Davis, Director

*Sandra M. DaDalt has signed this document on the indicated date on behalf of the above Directors and Officers for the Depositor pursuant to powers or attorney duly executed by such persons and a resolution of the Board of Directors authorizing use of powers of attorney for Officer signatures.  Resolution of the Board of Directors is incorporated herein by reference to the Registration Statement of Keyport Variable Account A on Form N-4, File No. 333-112506, filed on or about February 5, 2004.

EXHIBIT INDEX

D11	Rider
K	Legal Opinion
N	Consent of Independent Registered Public Accounting Firm