As Filed with the Securities and Exchange Commission on July 2, 2008

REGISTRATION NO. 333-83362

811-05846

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM N-4

REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933

Post-Effective Amendment No. 18

and

REGISTRATION STATEMENT UNDER THE INVESTMENT COMPANY ACT OF 1940

Amendment No. 83

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

(Exact Name of Registrant)

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

(Name of Depositor)

One Sun Life Executive Park

Wellesley Hills, Massachusetts 02481

(Address of Depositor's Principal Executive Offices)

Depositor's Telephone Number, including Area Code: (781) 237-6030

Sandra M. DaDalt, Assistant Vice President and Senior Counsel

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

One Sun Life Executive Park, SC 1335

Wellesley Hills, Massachusetts 02481

(Name and Address of Agent for Service)

Copies of Communications to:

Thomas C. Lauerman, Esq.

Jorden Burt LLP

1025 Thomas Jefferson Street, N.W.

SUITE 400 EAST

Washington, D.C. 20007-0805

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

0 immediately upon filing pursuant to paragraph (b) of Rule 485

£ on (date) pursuant to paragraph (b) of Rule 485

£ 60 days after filing pursuant to paragraph (a)(1) of Rule 485

R on September 2, 2008 pursuant to paragraph (a)(1) of Rule 485.

If appropriate, check the following box:

£ this post-effective amendment designates a new effective date for a previously filed post-effective amendment.

No filing fee is due because an indefinite amount of securities is deemed to have been registered in reliance on Section 24(f) of the Investment Company Act of 1940.

This Amendment No. 18 to the Registration Statement on Form N-4 (the "Registration Statement") (File Nos. 333-83362, 811-05846) is being filed pursuant to Rule 485(a) under the Securities Act of 1933, as amended. This Amendment does not otherwise delete, amend, or supersede any prospectus, statement of additional information, exhibit, or other information contained in Post-Effective Amendment No. 17 to the Registration Statement.

PART A

SUPPLEMENT DATED JULY 2, 2008

TO THE PROSPECTUS DATED MAY 1, 2008

FOR SUN LIFE FINANCIAL MASTERS EXTRA

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

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

Effective September 2, 2008, the above-captioned prospectus is amended as follows:

1.	Under the caption "PRODUCT HIGHLIGHTS," the last sentence of the paragraph entitled "The Accumulation Phase" is rewritten as follows:
		In addition, we will credit your Contract with interest, which we refer to as "Purchase Payment Interest", at a rate of 2% or 6% of each Purchase Payment based upon the interest rate option you choose when you apply for your Contract.

2.	The first paragraph under the subsection entitled "Purchase Payment Interest" is amended by replacing the current disclosure describing Option B with the following:
		Option B: The 6% Interest Option -- Under this option we will credit your Contract with interest at a rate of 6% of each Purchase Payment made on or after September 2, 2008. This option may not be available in all states.

3.	The definition of "PURCHASE PAYMENT INTEREST" in Appendix A is replaced with the following:
		PURCHASE PAYMENT INTEREST: The amount of extra interest the Company credits to a Contract at a rate of 2% or 6% based upon the interest rate option chosen at the time of application.

4.	Example 2 of "APPENDIX D - CALCULATION OF PURCHASE PAYMENT INTEREST (BONUS CREDIT)" is rewritten as follows:
		Example 2: Option B with no Withdrawals
		If you select Option B, the 6% Bonus Option, we will credit Purchase Payment Interest on all Purchase Payments made on or after September 2, 2008, at a rate of 6% of your Purchase Payment amount as illustrated below:
		Initial Purchase Payment of $50,000 receives 6% Purchase Payment Interest of $3,000.
		Subsequent Purchase Payments in the first Account Year of $20,000 receives Purchase Payment Interest of $1,200.
		Suppose an additional Purchase Payment of $60,000 is made in the third Account Year.  This Purchase Payment will receive 6% Purchase Payment Interest of $3,600.

Please retain this supplement with your prospectus for future reference.

Masters Extra

SEPTEMBER 2, 2008

SUN LIFE FINANCIAL MASTERS® EXTRA

VARIABLE AND FIXED ANNUITY

STATEMENT OF ADDITIONAL INFORMATION

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

TABLE OF CONTENTS

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

Advertising and Sales Literature

Tax Deferred Accumulation

Calculations

     Example of Variable Accumulation Unit Value Calculation

     Example of Variable Annuity Unit Calculation

     Example of Variable Annuity Payment Calculation

Distribution of the Contract

Custodian

Independent Registered Public AccountingFirm

Financial Statements

The Statement of Additional Information sets forth information which may be of interest to prospective purchasers of the Sun Life Financial Masters® Extra Variable and Fixed Annuity Contracts (the "Contracts") issued by Sun Life Assurance Company of Canada (U.S.) (the "Company" or "Sun Life (U.S.)") in connection with Sun Life of Canada (U.S.) Variable Account F (the "Variable Account") which is not included in the Prospectus dated May 1, 2008.  This Statement of Additional Information should be read in conjunction with the Prospectus, a copy of which may be obtained without charge from the Company by writing to Sun Life Assurance Company of Canada (U.S.), c/o Annuity Division, P.O. Box 9133, Wellesley Hills, Massachusetts 02481, or by telephoning (888) 786-2435.

The terms used in this Statement of Additional Information have the same meanings as in the Prospectus.

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THIS STATEMENT OF ADDITIONAL INFORMATION IS NOT A PROSPECTUS AND IS AUTHORIZED FOR DISTRIBUTION TO PROSPECTIVE PURCHASERS ONLY IF PRECEDED OR ACCOMPANIED BY A CURRENT PROSPECTUS.

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

Sun Life Financial Inc. ("Sun Life Financial"), a reporting company under the Securities Exchange Act of 1934 with common shares listed on the Toronto, New York and Philippine stock exchanges, is the ultimate corporate parent of Sun Life (U.S.). Sun Life Financial ultimately controls Sun Life (U.S.) through the following intervening companies: Sun Life of Canada (U.S.) Holdings, Inc., Sun Life Financial (U.S.) Investments LLC, Sun Life Financial (U.S.) Holdings, Inc., Sun Life Assurance Company of Canada - U.S. Operations Holdings, Inc., and Sun Life Global Investments, Inc.

ADVERTISING AND SALES LITERATURE

As set forth in the Prospectus, the Company may refer to the following organizations (and others) in its marketing materials:

A.M. BEST'S RATING SYSTEM is designed to evaluate the various factors affecting the overall performance of an insurance company in order to provide an opinion as to an insurance company's relative financial strength and ability to meet its contractual obligations. The procedure includes both a quantitative and qualitative review of each company.

FITCH CREDIT RATING Company's Insurance Company Claims Paying Ability Rating is an independent evaluation by a nationally accredited rating organization of an insurance company's ability to meet its future obligations under the contracts and products it sells. The rating takes into account both quantitative and qualitative factors.

LIPPER VARIABLE INSURANCE PRODUCTS PERFORMANCE ANALYSIS SERVICE is a publisher of statistical data covering the investment company industry in the United States and overseas. Lipper is recognized as the leading source of data on open-end and closed-end funds. Lipper currently tracks the performance of over 5,000 investment companies and publishes numerous specialized reports, including reports on performance and portfolio analysis, fee and expense analysis.

STANDARD & POOR'S insurance claims-paying ability rating is an opinion of an operating insurance company's financial capacity to meet obligations of its insurance policies in accordance with their terms.

VARDS (Variable Annuity Research Data Service) provides a comprehensive guide to variable annuity contract features and historical fund performance. The service also provides a readily understandable analysis of the comparative characteristics and market performance of funds inclusive in variable contracts.

MOODY'S Investors Services, Inc.'s insurance claims-paying rating is a system of rating an insurance company's financial strength, market leadership, and ability to meet financial obligations. The purpose of Moody's ratings is to provide investors with a simple system of gradation by which the relative quality of insurance companies may be noted.

STANDARD & POOR'S INDEX - broad-based measurement of changes in stock-market conditions based on the average performance of 500 widely held common stocks; commonly known as the Standard & Poor's 500 (S&P 500). The selection of stocks, their relative weightings to reflect differences in the number of outstanding shares, and publication of the index itself are services of Standard & Poor's Corporation, a financial advisory, securities rating, and publishing firm. The index tracks 400 industrial company stocks, 20 transportation stocks, 40 financial company stocks, and 40 public utilities.

NASDAQ-OTC Price Index - this index is based on the National Association of Securities Dealers Automated Quotations (NASDAQ) and represents all domestic over-the-counter stocks except those traded on exchanges and those having only one market maker, a total of some 3,500 stocks. It is market value-weighted and was introduced with a base of 100.00 on February 5, 1971.

DOW JONES INDUSTRIAL AVERAGE (DJIA) - price-weighted average of 30 actively traded blue chip stocks, primarily industrials, but including American Express Company and American Telephone and Telegraph Company. Prepared and Published by Dow Jones & Company, it is the oldest and most widely quoted of all the market indicators. The average is quoted in points, not dollars.

MORNINGSTAR, Inc. is an independent financial publisher offering comprehensive statistical and analytical coverage of open-end and closed-end funds and variable annuities. This coverage for mutual funds includes, among other information, performance analysis rankings, risk rankings (e.g. aggressive, moderate or conservative), and "style box" matrices. Style box matrices display, for equity funds, the investment philosophy and size of the companies in which the fund invests and, for fixed-income funds, interest rate sensitivity and credit quality of the investment instruments.

IBBOTSON ASSOCIATES, Inc. is a consulting firm that provides a variety of historical data, including total return, capital appreciation and income, on the stock market as well as other investment asset classes, and inflation. This information will be used primarily for comparative purposes and to illustrate general financial planning principles.

In its advertisements and other sales literature for the Variable Account and the Funds, the Company intends to illustrate the advantages of the Contracts in a number of ways:

DOLLAR-COST AVERAGING ILLUSTRATIONS. These illustrations will generally discuss the price-leveling effect of making regular investments in the same Sub-Accounts over a period of time, to take advantage of the trends in market prices of the portfolio securities purchased by those Sub-Accounts.

SYSTEMATIC WITHDRAWAL PROGRAM. A service provided by the Company, through which a Participant may take any distribution allowed by Internal Revenue Code Section 401 (a) (9) in the case of Qualified Contracts, or permitted under Internal Revenue Code Section 72 in the case of Non-Qualified Contracts, by way of a series of partial withdrawals. Withdrawals under this program may be fully or partially includible in income and may be subject to a 10% penalty tax. Consult your tax advisor.

THE COMPANY'S AND THE FUNDS' CUSTOMERS. Sales literature for the Variable Account and the Funds may refer to the number of clients which they serve.

THE COMPANY'S  ASSETS, SIZE. The Company may discuss its general financial condition (see, for example, the references to Standard & Poor's, Fitch and A.M. Best Company above); it may refer to its assets; and it may discuss its relative size and/or ranking among companies in the industry or among any sub-classification of those companies, based upon recognized evaluation criteria. For example, at December 31, 1998, the Company was the 36th largest U.S. life insurance company based upon overall assets.

COMPOUND INTEREST ILLUSTRATIONS. These will emphasize several advantages of the variable annuity contract. For example, but not by way of limitation, the literature may emphasize the potential savings through tax deferral; the potential advantage of the Variable Account over the Fixed Account; and the compounding effect when a participant makes regular deposits to his or her account.

The Company may use hypothetical illustrations of the benefits of tax deferral, including but not limited to the following chart:

The chart below assumes an initial investment of $10,000 which remains fully invested for the entire time period, an 8% annual return, and a 33% combined federal and state income tax rate. It compares how 3 different investments might fare over 10, 20, and 30 years. The first example illustrates an investment in a non-tax-deferred account and assumes that taxes are paid annually out of that account. The second example illustrates how the same investment would grow in a tax-deferred investment, such as an annuity. The third example illustrates the net value of the tax-deferred investment after paying taxes on the full account value.

	10 YEARS	20 YEARS	30 YEARS
Non-Tax-Deferred Account	$16,856	$28,413	$ 47,893
Tax-Deferred Account	$21,589	$46,610	$100,627
Tax-Deferred Account After Paying Taxes	$17,765	$34,528	$ 70,720

THIS ILLUSTRATION IS HYPOTHETICAL AND DOES NOT REPRESENT THE PROJECTED PERFORMANCE OF THE CONTRACT OR ANY OF ITS INVESTMENT OPTIONS. THE ILLUSTRATION DOES NOT REFLECT THE DEDUCTION OF ANY CHARGES OR FEES RELATED TO PORTFOLIO MANAGEMENT, MORTALITY AND EXPENSE, OR ACCOUNT ADMINISTRATION. TAXES ON EARNINGS WITHIN AN ANNUITY ARE DUE UPON WITHDRAWAL. WITHDRAWALS MAY ALSO BE SUBJECT TO SURRENDER CHARGES AND, IF MADE PRIOR TO AGE 59½, A 10% FEDERAL PENALTY TAX.

TAX-DEFERRED ACCUMULATION

In general, individuals who own annuity contracts are not taxed on increases in the value of their annuity contracts until some form of distribution is made under the contract. As a result, the annuity contract would benefit from tax deferral during the contract's accumulation phase; this would have the effect of permitting an investment in an annuity contract to grow more rapidly that a comparable investment under which increases in value are taxed on a current basis.

In reports or other communications to you or in advertising or sales materials, we may also describe the effects of tax-deferred compounding on the Variable Account's investment returns. We may illustrate these effects in charts or graphs and from time to time may include comparisons of returns under the Contract or in general on a tax-deferred basis, with the returns on a taxable basis. Different tax rates may be assumed. Any such illustrative chart or graph would show accumulations on an initial investment or Purchase Payment, assuming a given amount (including the applicable interest credit), hypothetical gross annual returns compounded annually, and a stated rate of return. The values shown for the taxable investment would not include any deduction for management fees or other expenses, but would assume the annual deduction of federal and state taxes from investment returns. The values shown for the Contract in a chart would reflect the deduction of Contract expenses, such as the mortality and expense risk charge, the 0.15% administrative charge, the 0.15%distribution fee, and the $50 annual Account Fee. In addition, the values shown would assume that the Participant has not surrendered his or her Contract or made any partial surrenders until the end of the period shown. The chart would assume a full surrender at the end of the period shown and the payment of federal and state taxes, at a rate of not more than 33%, on the amount in excess of the Purchase Payments.

In developing illustrative tax deferral charts, we will observe these general principles:

l	The assumed rate of earnings will be realistic.
l	The illustrative chart will accurately depict the effect of all fees and charges or provide a narrative that prominently discloses all fees and charges under the Contract.
l	Charts comparing accumulation values for tax-deferred and non-tax-deferred investments will depict the implications of any surrender.
l	A narrative accompanying the chart will prominently disclose that there may be a 10% tax penalty on a surrender by a Participant who has not reached age 59½ at the time of surrender.

The rates of return illustrated in any chart would be hypothetical and are not an estimate or guaranty of performance. Actual tax returns may vary among Participants.

CALCULATIONS

EXAMPLE OF VARIABLE ACCUMULATION UNIT VALUE CALCULATION

Suppose the net asset value of a Fund share at the end of the current valuation period is $18.38; at the end of the immediately preceding valuation period was $18.32; the Valuation Period is one day; and no dividends or distributions caused Fund shares to go "ex-dividend" during the current Valuation Period. $18.38 ÷ $18.32 = 1.00327511. Subtracting the one day risk factor for mortality and expense risks and the administrative expense charge of .00006375 (the daily equivalent of the current maximum charge of 2.30% on an annual basis) gives a net investment factor of 1.00321136.  If the value of the variable accumulation unit for the immediately preceding valuation period had been 14.5645672, the value for the current valuation period would be 14.6113394 (14.5645672 x 1.00321136).

EXAMPLE OF VARIABLE ANNUITY UNIT CALCULATION

Suppose the circumstances of the first example exist, and the value of an annuity unit for the immediately preceding valuation period had been 12.3456789. If the first variable annuity payment is determined by using an annuity payment based on an assumed interest rate of 3% per year, the value of the annuity unit for the current valuation period would be 12.3845294 (12.3456789 x 1.00322814 (the Net Investment Factor based on the daily equivalent of maximum annuity phase charge of 1.70% on an annual basis) x 0.99991902). 0.99991902 is the factor, for a one day Valuation Period that neutralizes the assumed interest rate of 3% per year used to establish the Annuity Payment Rates found in certain Contracts.

EXAMPLE OF VARIABLE ANNUITY PAYMENT CALCULATION

Suppose that a Participant Account is credited with 8,765.4321 variable accumulation units of a particular Sub-Account but is not credited with any fixed accumulation units; that the variable accumulation unit value and the annuity unit value for the particular Sub-Account for the valuation period which ends immediately preceding the annuity commencement date are 14.5645672 and 12.3456789 respectively; that the annuity payment rate for the age and option elected is $6.78 per $1,000; and that the annuity unit value on the day prior to the second variable annuity payment date is 12.3845294.  The first variable annuity payment would be $865.57 (8,765.4321 x 14.5645672 x 6.78 ÷ 1,000).  The number of annuity units credited would be 70.1112 ($865.57 ÷ 12.3456789) and the second variable annuity payment would be $868.29 (70.1112 x 12.3845294).

DISTRIBUTION OF THE CONTRACT

We offer the Contract on a continuous basis through the general distributor and principal underwriter of the Contracts, Clarendon Insurance Agency, Inc. ("Clarendon"). Clarendon also acts as the general distributor of certain other annuity contracts issued by the Company and its wholly-owned subsidiary, Sun Life Insurance and Annuity Company of New York, and variable life insurance contracts issued by the Company.

In addition to commissions, the Company may, from time to time, pay or allow additional promotional incentives, in the form of cash or other compensation. The Company reserves the right to offer these additional incentives only to certain broker-dealers that sell or are expected to sell during specified time periods certain minimum amounts of Contracts or Certificates or other contracts offered by the Company.  Promotional incentives may change at any time.

Commissions will not be paid to selling agents with respect to Participant Accounts established for the personal account of employees of the Company or any of its affiliates, or of persons engaged in the distribution of the Contract, or of immediate family members of such employees or persons. In addition, commissions may be waived or reduced in connection with certain transactions described in the Prospectus under the heading “Waivers; Reduced Charges; Credits; Special Guaranteed Interest Rates.”

CUSTODIAN

We are the Custodian of the assets of the Variable Account.  We will purchase Fund shares at net asset value in connection with amounts allocated to the Sub-Accounts in accordance with your instructions, and we will redeem Fund shares at net asset value for the purpose of meeting the contractual obligations of the Variable Account, paying charges relative to the Variable Account or making adjustments for annuity reserves held in the Variable Account.

INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

The auditor of the consolidated financial statements of Sun Life Assurance Company of Canada (U.S.) and Sun Life of Canada (U.S.) Variable Account F is Deloitte & Touche LLP, an independent registered public accounting firm.

FINANCIAL STATEMENTS

The financial statements of the Variable Account and Sun Life Assurance Company of Canada (U.S.) will be included by amendment. The consolidated financial statements of Sun Life Assurance Company of Canada (U.S.) will be provided as relevant to its ability to meet its financial obligations under the Conracts and should not be considered as bearing on the investment performance of the assets held in the Variable Account.

PART C

OTHER INFORMATION

Item 24. FINANCIAL STATEMENTS AND EXHIBITS

(a)	The following Financial Statements are included in the Registration Statement:
	A.	Condensed Financial Information - Accumulation Unit Values (Part A)
	B.	Financial Statements of the Depositor (Part B)(to be filed by amendment)
		Audited:
		1.	Consolidated Statements of Income, Years Ended December 31, 2007, 2006 and 2005;
		2.	Consolidated Balance Sheets, December 31, 2007 and 2006,
		3.	Consolidated Statements of Comprehensive Income, Years Ended December 31, 2007, 2006 and 2005;
		4.	Consolidated Statements of Stockholder's Equity, Years Ended December 31, 2007, 2006 and 2005;
		5.	Consolidated Statements of Cash Flows, Years Ended December 31, 2007, 2006 and 2005;
		6.	Notes to Consolidated Financial Statements; and
		7.	Report of Independent Registered Public Accounting Firm.
	C.	Financial Statements of the Registrant (Part B) (to be filed by amendment)
		1.	Statement of Condition, December 31, 2007;
		2.	Statement of Operations, Year Ended December 31, 2007;
		3.	Statements of Changes in Net Assets, Years Ended December 31, 2007 and December 31, 2006;
		4.	Notes to Financial Statements; and
		5.	Report of Independent Registered Public Accounting Firm.

(b) The following Exhibits are incorporated in the Registration Statement by reference unless otherwise indicated:

(1)	Resolution of Board of Directors of the Depositor dated December 3, 1985 authorizing the establishment of the Registrant (Incorporated herein by reference to the Registration Statement on Form N-4, File No. 333-37907, filed on October 14, 1997);
(2)	Not Applicable;
(3)(a)	Marketing Services Agreement between Sun Life Assurance Company of Canada (U.S.), Sun Life of Canada (U.S.) Distributors, Inc. and Clarendon Insurance Agency, Inc. (Incorporated herein by reference to Pre-Effective Amendment No. 1 to the Registration Statement on Form N-4, File No. 333-37907, filed on January 16, 1998);
(3)(b)(i)	Specimen Sales Operations and General Agent Agreement (Incorporated herein by reference to Pre-Effective Amendment No. 1 to the Registration Statement on Form N-4, File No. 333-37907, filed on January 16, 1998);
(3)(b)(ii)	Specimen Broker-Dealer Supervisory and Service Agreement (Incorporated herein by reference to Pre-Effective Amendment No. 1 to the Registration Statement on Form N-4, File No. 333-37907, filed on January 16, 1998);
(3)(b)(iii)	Specimen Registered Representatives Agent Agreement (Incorporated herein by reference to Pre-Effective Amendment No. 1 to the Registration Statement on Form N-4, File No. 333-37907, filed on January 16, 1998);
(4)(a)	Specimen Flexible Payment Combination Fixed/Variable Group Annuity Contract (Incorporated herein by reference to the Registration Statement on Form N-4, File No. 333-83256, filed on June 22, 2002);
(4)(b)	Specimen Certificate to be issued in connection with Contract filed as Exhibit 4(a) (Incorporated herein by reference to the Registration Statement on Form N-4, File No. 333-83256, filed on June 22, 2002);
(4)(c)	Specimen Flexible Payment Combination Fixed/Variable Individual Annuity Contract(Incorporated herein by reference to the Registration Statement on Form N-4, File No. 333-83256, filed on June 22, 2002);
(4)(d)	Specimen Secured Returns 2 Rider to Certificate filed as Exhibit (4)(b) (Incorporated herein by reference to the Registration Statement on Form N-4, File No. 333-115525, filed on May 14, 2004);
(4)(e)	Specimen Secured Returns 2 Rider to Flexible Payment Combination Fixed/Variable Individual Annuity Contract filed as Exhibit (4)(c) (Incorporated herein by reference to the Registration Statement on Form N-4, File No. 333-115525, filed on May 14, 2004);
(4)(f)	Specimen Secured Returns for Life Rider to Flexible Payment Combination Fixed/Variable Individual Annuity Contract filed as Exhibit (4)(c) (Incorporated herein by reference to Post-Effective Amendment No. 9 to the Registration Statement on Form N-4, File No. 333-83516, filed on August 2, 2005);
(4)(g)	Specimen Secured Returns for Life Plus Rider to Flexible Payment Combination Fixed/Variable Individual Annuity Contract filed as Exhibit (4)(c) (Incorporated herein by reference to Post-Effective Amendment No. 13 to the Registration Statement on Form N-4, File No. 333-83516, filed on February 3, 2006);
(4)(h)	Specimen INControl Benefit Rider to Flexible Payment Combination Fixed/Variable Individual Annuity Contract filed as Exhibit (4)(c) (Incorporated herein by reference to Post-Effective Amendment No. 19 to the Registration Statement on Form N-4, File No. 333-83516, filed on September 22, 2006);
(4)(i)	Specimen Rider to Flexible Payment Combination Fixed/Variable Individual Annuity Contract filed as Exhibit (4)(c) (Incorporated herein by reference to Post-Effective Amendment No. 19 to the Registration Statement on Form N-4, File No. 333-83516, filed on September 22, 2006);
(4)(j)	Specimen Retirement Income Escalator Rider to Flexible Payment Combination Fixed/Variable Individual Annuity Contract filed as Exhibit (4)(c) (Incorporated herein by reference to Post-Effective Amendment No. 25 to the Registration Statement on Form N-4, File No. 333-83516, filed on February 12, 2008);
(5)(a)	Specimen Application to be used with Contract filed as Exhibit 4(a) (Incorporated herein by reference to Pre-Effective Amendment No. 1 to the Registration Statement on Form N-4, File No. 333- 74884, filed on February 14, 2002);
(5)(b)	Specimen Application to be used with Certificate filed as Exhibit 4(b) and Contract filed as Exhibit 4(c) (Incorporated herein by reference to Pre-Effective Amendment No. 1 to the Registration Statement on Form N-4, File No. 333-74884, filed on February 14, 2002);
(6)(a)	Certificate of Incorporation of the Depositor (Incorporated herein by reference to the Depositor's Form 10-K, File No. 333-82824, filed on March 29, 2004);
(6)(b)	By-Laws of the Depositor, as amended March 19, 2004 (Incorporated herein by reference to the Depositor's Form 10-K, File No. 333-82824, filed on March 29, 2004);
(7)	Not Applicable;
(8)(a)	Participation Agreement by and between The Alger American Fund, the Depositor, and Fred Alger and Company, Incorporated (Incorporated herein by reference to Post-Effective Amendment No. 13 to the Registration Statement on Form N-4, File No. 33-41628, filed on April 26, 1999);
(8)(b)	Participation Agreement dated February 17, 1998 by and between Goldman Sachs Variable Insurance Trust, Goldman Sachs & Co. and the Depositor (Incorporated herein by reference to Post-Effective Amendment No. 13 to the Registration Statement on Form N-4, File No. 33-41628, filed on April 26, 1999);
(8)(c)	Amended and Restated Participation Agreement by and among MFS/Sun Life Services Trust, Sun Life Assurance Company of Canada (U.S.), Sun Life Insurance and Annuity Company of New York, and Massachusetts Financial Services Company (Incorporated herein by reference to Post-Effective Amendment No. 3 to the Registration Statement on Form N-4, File No. 333-107983, filed on May 28, 2004);
(8)(d)	Participation Agreement dated February 17, 1998 by and among the Depositor, AIM Variable Insurance Funds, Inc., AIM Distributors, Inc., and Clarendon Insurance Agency, Inc. (Incorporated herein by reference to Post-Effective Amendment No. 1 to the Registration Statement on Form N-4, File No. 333-82957, filed on February 3, 2000);
(8)(e)	Amended and Restated Participation Agreement dated December 18, 2004, by and among Sun Capital Advisers Trust, Sun Capital Advisers, Inc., Sun Life Assurance Company of Canada (U.S.) and Sun Life Insurance and Annuity Company of New York (Incorporated herein by reference to Post-Effective Amendment No. 8 to the Registration Statement on Form N-4, File No. 333-83516, filed on April 26, 2005);
(8)(f)	Participation Agreement dated April 30, 2001 by and among Rydex Variable Trust, Rydex Distributors, Inc., and Sun Life Assurance Company of Canada (U.S.). (Incorporated herein by reference to Post-Effective Amendment No. 7 to the Registration Statement on Form N-4, File No. 333-82957, filed on July 27, 2001);
(8)(g)	Amended and Restated Participation Agreement dated September 1, 2004 by and among Sun Life Assurance Company of Canada (U.S.), Variable Insurance Products Funds, and Fidelity Distributors Corporation. (Incorporated herein by reference to Post-Effective Amendment No. 8 to the Registration Statement on Form N-4, File No. 333-83516, filed on April 26, 2005);
(8)(h)	Participation Agreement dated May 1, 2001 by and among Sun Life Assurance Company of Canada (U.S.), the Depositor, Alliance Capital Management L.P., and Alliance Fund Distributors, Inc. (Incorporated herein by reference to Post-Effective Amendment No. 7 to the Registration Statement on Form N-4, File No. 333-82957, filed on July 27, 2001);
(8)(i)	Participation Agreement dated February 17, 1998 by and among Sun Life Assurance Company of Canada (U.S.), Lord Abbett Series Fund, Inc. and Lord, Abbett & Co. (Incorporated herein by reference to the Registration Statement of Keyport Variable Account A on Form N-4, File No. 333-112506, filed on February 5, 2004);
(8)(j)	Form of Participation Agreement (Incorporated herein by reference to the Registration Statement on Form N-4, File No. 333-74884, filed on December 10, 2001);
(8)(k)	Participation Agreement Among Liberty Variable Investment Trust, Liberty Funds Distributor, Inc., and Sun Life Assurance Company of Canada (U.S.) (Incorporated herein by reference to the Registration Statement of Keyport Variable Account A on Form N-4, File No. 333-114126, filed on April 1, 2004);
(8)(l)	Participation Agreement Among SteinRoe Variable Investment Trust, Liberty Funds Distributor, Inc., and Sun Life Assurance Company of Canada (U.S.) (Incorporated herein by reference to the Registration Statement of Keyport Variable Account A on Form N-4, File No. 333-114126, filed on April 1, 2004);
(8)(m)	Participation Agreement Among Wanger Advisors Funds, Wanger Asset Management LP and Sun Life Assurance Company of Canada (U.S.) (Incorporated herein by reference to the Registration Statement of Keyport Variable Account A on Form N-4, File No. 333-114126, filed on April 1, 2004);
(8)(n)	Participation Agreement Among Franklin Templeton Variable Insurance Products Trust, Franklin Templeton Distributors, Inc., Sun Life Assurance Company of Canada (U.S.), Sun Life Insurance and Annuity Company of New York and Clarendon Insurance Agency, Inc. (Incorporated herein by reference to the Registration Statement of KBL Variable Account A on Form N-4, File No. 333-102278, filed on December 31, 2002);
(8)(o)	Participation Agreement 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 the Registration Statement of Keyport Variable Account A on Form N-4, File No. 333-112506, filed on February 5, 2004);
(8)(p)	Participation Agreement Among Oppenheimer Variable Account Funds, Oppenheimer Funds, Inc. and Sun Life Assurance Company of Canada (U.S.) (Incorporated herein by reference to the Registration Statement of Keyport Variable Account A on Form N-4, File No. 333-112506, filed on February 5, 2004);
(8)(q)	Participation Agreement dated February 15, 2005 among Nations Separate Account Trust, BACAP Distributors, LLC, Sun Life Assurance Company of Canada (U.S.) and Sun Life Insurance and Annuity Company of New York (Incorporated herein by reference to Post-Effective Amendment No. 8 to Registration Statement on Form N-4, File No. 333-83516, filed on April 26, 2005);
(8)(r)	Participation Agreement by and among Wanger Advisors Trust, Columbia Funds Distributors, Inc., Sun Life Assurance Company of Canada (U.S.), and Sun Life Insurance and Annuity Company of New York (Incorporated herein by reference to Post-Effective Amendment No. 8 to Registration Statement on Form N-4, File No. 333-83516, filed on April 26, 2005);
(8)(s)	Participation Agreement by and among Liberty Variable Investment 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 Post-Effective Amendment No. 8 to Registration Statement on Form N-4, File No. 333-83516, filed on April 26, 2005);
(8)(t)	Participation Agreement, dated December 3, 2007, by and among Sun Life Assurance Company of Canada (U.S.), Sun Life Insurance and Annuity Company of New York, Lazard Asset Management Securities LLC, and Lazard Retirement Series, Inc. (Incorporated herein by reference to Post-Effective Amendment No. 25 to the Registration Statement on Form N-4, File No. 333-83516, filed on February 12, 2008);
(8)(u)	Participation Agreement, dated August 6, 2004, by and among Sun Life Assurance Company of Canada (US), Van Kampen Life Investments Trust, Van Kampen Funds Inc., and Van Kampen Asset Management. (Incorporated herein by reference to Post-Effective Amendment No. 4 to the Registration Statement on Form N-6 of Sun Life of Canada (US) Variable Account I, File No. 333-100831, filed on April 29, 2005);
(8)(v)	Participation Agreement, dated May 1, 2004, by and among Sun Life Assurance Company of Canada (U.S.), The Universal Institutional Funds, Inc., Morgan Stanley & Co. Incorporated and Morgan Stanley Investment Management Inc. (Incorporated herein by reference to Post-Effective Amendment No. 5 to the Registration Statement on Form N-6 of Sun Life of Canada (US) Variable Account G, File No. 333-111688, filed on April 27, 2007);
(8)(w)	Participation Agreement, dated December 3, 2007, by and among Sun Life Assurance Company of Canada (U.S.), The Huntington Funds, Edgewood Services, Inc., and Huntington Asset Advisors, Inc. (Incorporated herein by reference to Post-Effective Amendment No. 25 to the Registration Statement on Form N-4, File No. 333-83516, filed on February 12, 2008);
(9)	Opinion of Counsel as to the legality of the securities being registered and Consent to its use (Incorporated herein by reference to the Registration Statement on Form N-4, File No. 333-83256, filed on February 22, 2002);
(10)(a)	Consent of Independent Registered Public Accounting Firm (to be filed by amendment);
(11)	Financial Statement Schedules I and VI (Incorporated herein by reference to the Depositor's Form 10-K Annual Report for the fiscal year ended December 31, 2007, filed on March 27, 2008);
(12)	Not Applicable;
(13)	Schedule for Computation of Performance Quotations (Incorporated herein by reference to Post-Effective Amendment No. 10 to the Registration Statement on Form N-4, File No. 33-41628, filed on April 29, 1998);
(14)	Not Applicable;
(15)(a)	Powers of Attorney (Incorporated herein by reference to Post-Effective Amendment No. 17 to the Registration Statement on Form N-4, File No. 333-83362, filed on May 1, 2008);
(15)(b)	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 on February 5, 2004);
(16)	Organizational Chart (Incorporated herein by reference to Post-Effective Amendment No. 25 to the Registration Statement on Form N-4, File No. 333-83516, filed on February 12, 2008).

Item 25. 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, Ontario Canada  M5H 1J9	Director and Chairman
Scott M. Davis Sun Life Assurance Company of Canada (U.S.) One Sun Life Executive Park Wellesley Hills, MA  02481	Senior Vice President and General Counsel and 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
Ronald H. Friesen Sun Life Assurance Company of Canada (U.S.) One Sun Life Executive Park Wellesley Hills, MA  02481	Senior Vice President and Chief Financial Officer and Treasurer and Director
Richard P. McKenney Sun Life Assurance Company of Canada 150 King Street West Toronto, Ontario Canada  M5H 1J9	Director
Robert C. Salipante Sun Life Assurance Company of Canada (U.S.) One Sun Life Executive Park Wellesley Hills, MA 02481	President and Director
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
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
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
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
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
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
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

Item 26. PERSONS CONTROLLED BY OR UNDER COMMON CONTROL WITH THE DEPOSITOR OR 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-4, File No. 333-83516, filed February 12, 2008.

None of the companies listed in such Exhibit 16 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 27. NUMBER OF CONTRACT OWNERS

As of June 30, 2008 there were 5,592 qualified and 5,311 non-qualified contract owners.

Item 28. 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 29. PRINCIPAL UNDERWRITERS

(a) Clarendon Insurance Agency, Inc., 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, G, I, 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
Michele G. Van Leer	Director
Scott M. Davis	Director
Ronald H. Friesen	Director
Michael S. Bloom	Secretary
Ann B. Teixeira	Assistant Vice President, Compliance
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 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) Inapplicable.

Item 30. 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 31. MANAGEMENT SERVICES

Not Applicable.

Item 32. UNDERTAKINGS

The Registrant hereby undertakes:

(a)	To file a post-effective amendment to this Registration Statement as frequently as is necessary to ensure that the audited financial statements in the Registration Statement are never more than 16 months old for so long as payments under the variable annuity Contracts may be accepted;
(b)	To include either (1) as part of any application to purchase a Contract offered by the prospectus, a space that an Applicant can check to request a Statement of Additional Information, or (2) a post card or similar written communication affixed to or included in the prospectus that the Applicant can remove to send for a Statement of Additional Information;
(c)	To deliver any Statement of Additional Information and any financial statements required to be made available under SEC Form N-4 promptly upon written or oral request.
(d)	Representation with respect to Section 26(f)(2)(A) of the Investment Company Act of 1940: Sun Life Assurance Company of Canada (U.S.) represents that the fees and charges deducted under the Contracts, in the aggregate, are reasonable in relation to the services rendered, the expenses expected to be incurred, and the risks assumed by the insurance company.
	The Registrant is relying on the no-action letter issued by the Division of Investment Management of the Securities and Exchange Commission to American Council of Life Insurance, Ref. No. IP-6-88, dated November 28, 1988, the requirements for which have been complied with by the Registrant.

SIGNATURES

As required by the Securities Act of 1933 and the Investment Company Act of 1940, the Registrant certifies that it meets all of the requirements of Securities Act Rule 485 for effectiveness of this Post-Effective Amendment to the Registration Statement and 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 1st day of July, 2008.

SUN LIFE OF CANADA (U.S.) VARIABLE ACCOUNT F
(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 and Senior Counsel

As required by the Securities Act of 1933, this Registration Statement has been signed below 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*	President and Director	July 1, 2008
Robert C. Salipante	(Principal Executive Officer)
/s/ Ronald H. Friesen*	Senior Vice President and Chief Financial Officer	July 1, 2008
Ronald H. Friesen	and Treasurer and Director
	(Principal Financial Officer)
/s/ Michael K. Moran*	Vice President and Chief Accounting Officer	July 1, 2008
Michael K. Moran	(Principal Accounting Officer)
*By: /s/ Sandra M. DaDalt	Attorney-in-Fact for:	July 1, 2008
Sandra M. DaDalt	Thomas A. Bogart, Director
	Scott M. Davis, Director
	Michele G. Van Leer, Director
	Richard P. McKenney, 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. Powers of attorney are included herein as Exhibit 15(a).