November 8, 2012

Via EDGAR

Ms. Sharon M. Blume

Assistant Chief Accountant

U.S. Securities and Exchange Commission

Division of Corporation Finance

Washington, D.C. 20549

Form 10-K for the year ended December 31, 2011 and the 10-Q for the quarterly period ended June 30, 2012

File No. 000-32897

Dear Ms. Blume:

Please find attached the response to your Staff Letter request of October 25, 2012 prepared by the staff of United Security Bancshares (the “Company”). The responses are in the same order as the order of the comments in the Staff Letter. We have also attached appendixes to show the changes in the proposed disclosure from the previous disclosures in the filed periodic reports in issue.

Should you have any further questions, please do not hesitate to contact the undersigned.

Mr. Gary S. Findley, Esq.

With respect to the responses to the Staff letter of October 25, 2012 provided by United Security Bancshares (the “Company”) and filed with the SEC, we understand that,

/s/ Dennis R. Woods

Dennis R. Woods

Chief Executive Officer

United Security Bancshares

/s/ Kenneth L. Donahue

Kenneth L. Donahue

Chief Administrative Officer

United Security Bancshares

/s/ Richard B. Shupe

Richard B. Shupe

Chief Financial Officer

United Security Bancshares

Item 1 (10-K December 31, 2011)

General

1. Please use the correct file number of 000-32897 in future 1934 Act filings.

Response:

We have corrected the file number to 000-32897 beginning with the September 30, 2012 10-Q filing and will use that file number in future filings.

We agree to use file number 000-32897 in our future filings as discussed in the aforementioned response.

Item 2 (10-K for December 31, 2011)

Note 9 to Consolidated Financial Statements – Taxes on Income, page 95.

2. Please tell us and revise your future filings to specifically detail the positive and negative evidence used to support your decision under paragraphs 21 & 22 of ASC 740-10-30.

Response:

At December 31, 2011, the Company determined the realizability of the net deferred tax asset based upon positive and negative evidence as required under ASC 740-10-30. We performed the analysis considering both tax planning strategies and future earnings as a basis for utilizing the deferred tax assets. Although we analyzed tax planning strategies, including the possible sale of certain Bank premises and the surrender of Bank Owned Life Insurance, the primary focus of our analysis was on projected future earnings in the light of recent losses. We have attached our written analysis (Exhibit 1) which not only provides validity for a 5-year income projection, also supports our belief that the losses experienced over the last three calendar years are an aberration rather than a continuing trend.

The five year income projections were discounted for future periods (probability factor of 75% during the next two years, declining to 50% in the fifth year.) Adjustments were made for anticipated decreases in provisions for loan losses, as well as reduced OREO impairment charges and operating expenses.

The following is the disclosure we are providing in the September 30, 2012 10-Q:

The Company periodically evaluates its deferred tax assets to determine whether a valuation allowance is required based upon a determination that some or all of the deferred assets may not be ultimately realized. At September 30, 2012 and December 31, 2011, the Company had a recorded valuation allowance of $3.7 million. The Company performs an analysis of the valuation allowance considering both tax planning strategies and future earnings as a basis for utilizing the deferred tax assets. The tax planning strategies include the sale of certain bank premises and the surrender of Bank Owned Life Insurance. In its review of a requirement for a valuation allowance, the Company identifies both positive and negative evidence to determine whether a valuation allowance is required. Negative evidence would include pretax losses recorded during each of the last three calendar years. These losses were the result of the severe economic downturn that began in 2008 resulting in substantial increases in the provision for loan losses as well as impairment losses related to other real estate owned through foreclosure, goodwill, and private label residential mortgage obligations. At December 31, 2011, the Company performed an analysis of future projected earnings to provide positive evidence that sufficient earnings would be generated to utilize the deferred tax assets. Underlying assumptions included continued reductions in nonperforming assets and general improvements in the economy, resulting in reduced provisions for loans losses and impairment charges, as well as reductions in expenses related to other real estate owned. Based upon this analysis, the Company has concluded that the valuation allowance of $3.7 million at September 30, 2012 and December 31, 2011 is reasonable.

We agree to undertake to include in our future filings requiring financial statements (Regulation S-X and Item 303 of Regulation S-K) the expanded disclosures as discussed in the aforementioned response.

Item 3 (10-Q for June 30, 2012)

Note 2 to Consolidated Financial Statements – Investment Securities Available for Sale and Other Investments, page 10.

3. Please tell us and expand future filings to state the valuation technique used on loans less than 60 or more days past due. In addition, tell us if this represents a change in company’s OTTI methodology, the difference between the cash flow valuation technique used at December 31, 2011 and this technique, and if applicable, why this change was made

Response:

The valuation technique used in the June 30, 2012 other-than-temporary impairment analysis does not represent a change from the technique utilized at December 31, 2011.

The following summarizes the methodology utilized for all loans evaluated at December 31, 2011 and June 30, 2012, as well as the expanded disclosure we will include in the September 30, 2012 10-Q:

The cash flow assumptions used in the evaluation at June 30, 2012 utilized a discounted cash flow valuation technique applying a “Liquidation Scenario” whereby loans are evaluated by delinquency and are assigned probability of default and loss factors deemed appropriate in the current economic environment. The liquidation scenario assumes that all loans 60 or more days past due are liquidated and losses are realized over a period of between six and twenty-four months based upon current 3-month trailing loss severities obtained from reputable financial data sources. In determining fair value under the discounted cash flow analysis, all loans within the mortgage pools, including those less than 60 or more past due, are evaluated for other-than-temporary impairment utilizing the following components:

The prepayment, default and loss severity assumptions result in forecasted cumulative loss rates.  The resulting cumulative loss rates are benchmarked to other sources.

We agree to undertake to include in our future filings requiring financial statements (Regulation S-X) the expanded disclosures as discussed in the aforementioned response.

Item 4 (10-Q for June 30, 2012)

Note 2 to Consolidated Financial Statements – Investment Securities Available for Sale and Other Investments, page 10.

4. Please provide us your OTTI analysis regarding the private label mortgage-backed security that you stated was impaired but for which no impairment was taken or advise the staff, as applicable.

Response:

We have included a copy of the other-than-temporary impairment analysis for the periods ended March 31, 2012 and June 30, 2012, as Exhibit 2 and Exhibit 3, respectively. Refer to Appendix A on both the March 31, 2012 and the June 30, 2012 analysis for detail on which securities were subject to other-than-temporary impairment (OTTI) adjustments at each period end. At March 30, 2012 the RALI 2006-QS16 A10 and the CWALT 2007-8CB A9 securities did not have OTTI adjustments, while at June 30, 2012, only the RALI 2006-QS16 A10 did not have an OTTI adjustment.

Item 5 (10-Q for June 30, 2012)

Note 3 to Consolidated Financial Statements - Loans and leases Troubled Debt Restructurings, page 16

5. Please tell us and revise future filings to provide a roll forward of your troubled debt restructurings (TDR) for each period presented and quantify the related allowance for loan losses. In addition, disclose your accounting policy for removing loans from TDR classification.

Response:

We have included the TDR tables for June 30, 2012 here, and we have revised the September 30, 2012 10-Q filing to include the TDR roll forward information that you have requested in Item 5.

Although the Company does not have a policy which specifically addresses when a loan may be removed from TDR classification, as a matter of practice, loans classified as TDR’s generally remain classified as such until the loan either reaches maturity or its outstanding balance is paid off. We have also added in the September 30, 2012 10-Q filing a discussion of the Company’s accounting policy for removing loans classified as TDR.

We agree to undertake to include in our future filings requiring financial statements (Regulation S-X) the expanded disclosures as discussed in the aforementioned response.

Exhibit 1

Exhibit 2

Exhibit 3