Form N-Q

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, DC 20549

FORM N-Q


QUARTERLY SCHEDULE OF PORTFOLIO HOLDINGS OF REGISTERED MANAGEMENT INVESTMENT COMPANY

Investment Company Act file number         811-21212         

        Nuveen Insured California Tax-Free Advantage Municipal Fund         
(Exact name of registrant as specified in charter)

Nuveen Investments
        333 West Wacker Drive, Chicago, Illinois 60606         
(Address of principal executive offices) (Zip code)


Kevin J. McCarthy Vice President and Secretary
        333 West Wacker Drive, Chicago, Illinois 60606         
(Name and address of agent for service)

Registrant's telephone number, including area code:         312-917-7700        

Date of fiscal year end:            2/28          

Date of reporting period:         5/31/09         

Form N-Q is to be used by management investment companies, other than small business investment companies registered on Form N-5 (§§ 239.24 and 274.5 of this chapter), to file reports with the Commission, not later than 60 days after the close of the first and third fiscal quarters, pursuant to rule 30b1-5 under the Investment Company Act of 1940 (17 CFR 270.30b1-5). The Commission may use the information provided on Form N-Q in its regulatory, disclosure review, inspection, and policymaking roles.

A registrant is required to disclose the information specified by Form N-Q, and the Commission will make this information public. A registrant is not required to respond to the collection of information contained in Form N-Q unless the Form displays a currently valid Office of Management and Budget ("OMB") control number. Please direct comments concerning the accuracy of the information collection burden estimate and any suggestions for reducing the burden to the Secretary, Securities and Exchange Commission, 450 Fifth Street, NW, Washington, DC 20549-0609. The OMB has reviewed this collection of information under the clearance requirements of 44 U.S.C. § 3507.

Item 1. Schedule of Investments

    Portfolio of Investments (Unaudited)             
    Nuveen Insured California Tax-Free Advantage Municipal Fund (NKX)             
    May 31, 2009             
Principal        Optional Call         
Amount (000)    Description (1)    Provisions (2)    Ratings (3)    Value 
    Consumer Staples – 3.4% (2.4% of Total Investments)             
$         6,070    Golden State Tobacco Securitization Corporation, California, Enhanced Tobacco Settlement    6/22 at 100.00    BBB   $   2,714,686 
     Asset-Backed Bonds, Series 2007A-2, 0.000%, 6/01/37             
    Health Care – 17.7% (12.4% of Total Investments)             
1,800    California Infrastructure Economic Development Bank, Revenue Bonds, Kaiser Hospital Assistance    8/11 at 102.00    A+    1,777,248 
     LLC, Series 2001A, 5.550%, 8/01/31             
662    California Statewide Communities Development Authority, Revenue Bonds, Saint Joseph Health    7/18 at 100.00    AAA    613,965 
     System, Trust 2554, 18.389%, 7/01/47 – FSA Insured (IF)             
4,000    California Statewide Community Development Authority, Insured Health Facility Revenue Bonds,    7/17 at 100.00    AAA    3,981,840 
     Catholic Healthcare West, Series 2008K, 5.500%, 7/01/41 – AGC Insured             
1,815    California Statewide Community Development Authority, Revenue Bonds, Kaiser Permanante System,    3/16 at 100.00    A+    1,574,694 
     Series 2006, 5.000%, 3/01/41             
1,120    California Statewide Community Development Authority, Revenue Bonds, Kaiser Permanente System,    3/16 at 100.00    AAA    1,618,590 
     Trust 11672, 19.035%, 3/01/41 – BHAC Insured (IF)             
4,060    California Statewide Community Development Authority, Revenue Bonds, Sherman Oaks Health    No Opt. Call    A    4,317,648 
     System, Series 1998A, 5.000%, 8/01/22 – AMBAC Insured             
13,457    Total Health Care            13,883,985 
    Housing/Multifamily – 1.4% (1.0% of Total Investments)             
1,165    Poway, California, Housing Revenue Bonds, Revenue Bonds, Poinsettia Mobile Home Park, Series    5/13 at 102.00    AA–    1,130,842 
     2003, 5.000%, 5/01/23             
    Long-Term Care – 3.7% (2.6% of Total Investments)             
1,000    ABAG Finance Authority for Non-Profit Corporations, California, Insured Senior Living Revenue    11/12 at 100.00    A    978,580 
     Bonds, Odd Fellows Home of California, Series 2003A, 5.200%, 11/15/22             
2,000    California Health Facilities Financing Authority, Cal-Mortgage Insured Revenue Bonds, Northern    1/13 at 100.00    A    1,897,980 
     California Retired Officers Community Corporation – Paradise Valley Estates, Series 2002,             
     5.250%, 1/01/26             
3,000    Total Long-Term Care            2,876,560 
    Tax Obligation/General – 18.7% (13.2% of Total Investments)             
2,000    Butte-Glenn Community College District, Butte and Glenn Counties, California, General    8/12 at 101.00    A1    2,024,620 
     Obligation Bonds, Series 2002A, 5.000%, 8/01/26 – MBIA Insured             
1,030    Fontana Unified School District, San Bernardino County, California, General Obligation Bonds,    8/18 at 100.00    AAA    1,107,281 
     Trust 2668, 8.739%, 8/01/28 – FSA Insured (IF)             
450    Fremont Unified School District, Alameda County, California, General Obligation Bonds, Series    8/12 at 101.00    AA–    436,379 
     2002A, 5.000%, 8/01/25 – FGIC Insured             
2,000    Los Angeles, California, General Obligation Bonds, Series 2002A, 5.000%, 9/01/22 – MBIA Insured    9/12 at 100.00    AA    2,090,200 
1,000    Murrieta Valley Unified School District, Riverside County, California, General Obligation    9/13 at 100.00    AA–    1,012,530 
     Bonds, Series 2003A, 5.000%, 9/01/26 – FGIC Insured             
1,000    Murrieta Valley Unified School District, Riverside County, California, General Obligation    9/17 at 100.00    AAA    917,750 
     Bonds, Series 2007, 4.500%, 9/01/30 – FSA Insured             
140    Roseville Joint Union High School District, Placer County, California, General Obligation    8/15 at 100.00    AA–    142,219 
     Bonds, Series 2006B, 5.000%, 8/01/27 – FGIC Insured             
3,000    San Diego Unified School District, California, General Obligation Bonds, Election of 1998,    7/10 at 100.00    AA    3,118,980 
     Series 2000B, 5.125%, 7/01/22 – MBIA Insured             
3,855    San Rafael City High School District, Marin County, California, General Obligation Bonds,    8/12 at 100.00    AAA    3,889,579 
     Series 2003A, 5.000%, 8/01/28 – FSA Insured             
14,475    Total Tax Obligation/General            14,739,538 
    Tax Obligation/Limited – 45.1% (31.7% of Total Investments)             
550    Baldwin Park Public Financing Authority, California, Sales Tax and Tax Allocation Bonds,    8/13 at 102.00    BBB    538,395 
     Puente Merced Redevelopment Project, Series 2003, 5.250%, 8/01/21             
1,165    Burbank Public Financing Authority, California, Revenue Refunding Bonds, Golden State    12/13 at 100.00    A    1,133,592 
     Redevelopment Project, Series 2003A, 5.250%, 12/01/22 – AMBAC Insured             
4,000    California State Public Works Board, Lease Revenue Bonds, Department of General Services,    12/12 at 100.00    A    3,669,520 
     Capital East End Project, Series 2002A, 5.000%, 12/01/27 – AMBAC Insured             
170    Capistrano Unified School District, Orange County, California, Special Tax Bonds, Community    9/15 at 100.00    AA–    158,952 
     Facilities District, Series 2005, 5.000%, 9/01/24 – FGIC Insured             
525    Chino Redevelopment Agency, California, Merged Chino Redevelopment Project Area Tax Allocation    9/16 at 101.00    A    428,290 
     Bonds, Series 2006, 5.000%, 9/01/38 – AMBAC Insured             
1,610    Folsom Public Financing Authority, California, Special Tax Revenue Bonds, Series 2004A,    9/12 at 102.00    A    1,554,069 
     5.000%, 9/01/21 – AMBAC Insured             
2,195    Golden State Tobacco Securitization Corporation, California, Enhanced Tobacco Settlement    6/15 at 100.00    AAA    1,881,263 
     Revenue Bonds, Drivers Trust 2091, 12.225%, 6/01/45 – AGC Insured (IF)             
3,285    Golden State Tobacco Securitization Corporation, California, Tobacco Settlement Asset-Backed    6/15 at 100.00    A    2,719,750 
     Revenue Bonds, Series 2005A, 5.000%, 6/01/45 – AMBAC Insured             
1,000    Hesperia Public Financing Authority, California, Redevelopment and Housing Projects Tax    9/17 at 100.00    Baa1    722,670 
     Allocation Bonds, Series 2007A, 5.000%, 9/01/37 – SYNCORA GTY Insured             
5,540    Irvine Public Facilities and Infrastructure Authority, California, Assessment Revenue Bonds,    9/13 at 100.00    A    5,023,173 
     Series 2003C, 5.000%, 9/02/21 – AMBAC Insured             
315    Los Angeles Community Redevelopment Agency, California, Lease Revenue Bonds, Manchester Social    9/15 at 100.00    A2    283,380 
     Services Project, Series 2005, 5.000%, 9/01/37 – AMBAC Insured             
1,770    Los Angeles Unified School District, California, Certificates of Participation, Administration    10/12 at 100.00    A+    1,726,316 
     Building Project II, Series 2002C, 5.000%, 10/01/27 – AMBAC Insured             
2,000    Los Angeles, California, Certificates of Participation, Municipal Improvement Corporation,    6/13 at 100.00    AA–    1,975,220 
     Series 2003AW, 5.000%, 6/01/33 – AMBAC Insured             
1,500    Los Angeles, California, Municipal Improvement Corporation, Lease Revenue Bonds, Police    1/17 at 100.00    AA–    1,412,985 
     Headquarters, Series 2006A, 4.750%, 1/01/31 – FGIC Insured             
1,500    Los Osos, California, Improvement Bonds, Community Services Wastewater Assessment District 1,    9/10 at 103.00    AA–    1,194,675 
     Series 2002, 5.000%, 9/02/33 – MBIA Insured             
150    Rialto Redevelopment Agency, California, Tax Allocation Bonds, Merged Project Area, Series    9/15 at 100.00    A–    129,045 
     2005A, 5.000%, 9/01/35 – SYNCORA GTY Insured             
190    Roseville, California, Certificates of Participation, Public Facilities, Series 2003A, 5.000%,    8/13 at 100.00    AA–    175,110 
     8/01/25 – AMBAC Insured             
    San Buenaventura, California, Certificates of Participation, Golf Course Financing Project,             
    Series 2002D:             
3,000     5.000%, 2/01/27 – AMBAC Insured    2/12 at 100.00    AA–    2,927,580 
3,300     5.000%, 2/01/32 – AMBAC Insured    2/12 at 100.00    AA–    3,083,388 
1,200    San Diego Redevelopment Agency, California, Subordinate Lien Tax Increment and Parking Revenue    9/09 at 101.00    Baa2    1,061,544 
     Bonds, Centre City Project, Series 2003B, 5.250%, 9/01/26             
2,770    San Jose Financing Authority, California, Lease Revenue Refunding Bonds, Civic Center Project,    6/12 at 100.00    AA+    2,758,726 
     Series 2002B, 5.000%, 6/01/32 – AMBAC Insured             
1,000    San Jose Redevelopment Agency, California, Tax Allocation Bonds, Merged Project Area, Series    8/15 at 100.00    AA–    862,380 
     2005A, 5.000%, 8/01/28 – MBIA Insured             
38,735    Total Tax Obligation/Limited            35,420,023 
    Transportation – 10.2% (7.2% of Total Investments)             
5,480    Bay Area Governments Association, California, BART SFO Extension, Airport Premium Fare Revenue    8/12 at 100.00    A    5,307,762 
     Bonds, Series 2002A, 5.000%, 8/01/26 – AMBAC Insured             
2,000    Foothill/Eastern Transportation Corridor Agency, California, Toll Road Revenue Bonds, Series    1/10 at 100.00    BBB–    1,421,420 
     1995A, 5.000%, 1/01/35             
1,300    San Francisco Airports Commission, California, Revenue Bonds, San Francisco International    5/10 at 101.00    AA–    1,304,147 
     Airport, Second Series 2000, Issue 26B, 5.000%, 5/01/25 – FGIC Insured             
8,780    Total Transportation            8,033,329 
    U.S. Guaranteed – 20.6% (14.4% of Total Investments) (4)             
1,000    Berryessa Union School District, Santa Clara County, California, General Obligation Bonds,    8/12 at 100.00    AAA    1,113,780 
     Series 2003C, 5.000%, 8/01/21 (Pre-refunded 8/01/12) – FSA Insured             
    California State, General Obligation Bonds, Series 2002:             
1,290     5.000%, 4/01/27 (Pre-refunded 4/01/12) – AMBAC Insured    4/12 at 100.00    AAA    1,421,632 
2,945     5.250%, 4/01/30 (Pre-refunded 4/01/12) – SYNCORA GTY Insured    4/12 at 100.00    A2 (4)    3,265,946 
500    California, General Obligation Bonds, Series 2004, 5.250%, 4/01/34 (Pre-refunded 4/01/14)    4/14 at 100.00    AAA    579,835 
1,625    Golden State Tobacco Securitization Corporation, California, Tobacco Settlement Asset-Backed    6/13 at 100.00    AAA    1,971,044 
     Revenue Bonds, Series 2003A-2, 7.900%, 6/01/42 (Pre-refunded 6/01/13)             
2,030    Hacienda La Puente Unified School District, Los Angeles County, California, General Obligation    8/13 at 100.00    AAA    2,315,560 
     Bonds, Series 2003B, 5.000%, 8/01/27 (Pre-refunded 8/01/13) – FSA Insured             
1,260    Rancho Mirage Joint Powers Financing Authority, California, Revenue Bonds, Eisenhower Medical    7/14 at 100.00    A3 (4)    1,500,143 
     Center, Series 2004, 5.875%, 7/01/26 (Pre-refunded 7/01/14)             
1,220    San Jose Redevelopment Agency, California, Tax Allocation Bonds, Merged Area Redevelopment    8/10 at 101.00    AA– (4)    1,295,433 
     Project, Series 2002, 5.000%, 8/01/32 (Pre-refunded 8/01/10) – MBIA Insured             
2,390    Solano County, California, Certificates of Participation, Series 2002, 5.250%, 11/01/24    11/12 at 100.00    AA– (4)    2,701,967 
     (Pre-refunded 11/01/12) – MBIA Insured             
14,260    Total U.S. Guaranteed            16,165,340 
    Utilities – 3.0% (2.1% of Total Investments)             
1,000    Anaheim Public Finance Authority, California, Second Lien Electric Distribution Revenue Bonds,    10/14 at 100.00    AA–    1,046,870 
     Series 2004, 5.250%, 10/01/21 – MBIA Insured             
945    Long Beach Bond Finance Authority, California, Natural Gas Purchase Revenue Bonds, Series    No Opt. Call    A    806,945 
     2007A, 5.500%, 11/15/37             
275    Los Angeles Department of Water and Power, California, Power System Revenue Bonds, Series    7/13 at 100.00    AA–    286,976 
     2003A-2, 5.000%, 7/01/21 – MBIA Insured             
310    Merced Irrigation District, California, Electric System Revenue Bonds, Series 2005, 5.125%,    9/15 at 100.00    BBB–    248,437 
     9/01/31 – SYNCORA GTY Insured             
2,530    Total Utilities            2,389,228 
    Water and Sewer – 14.1% (9.9% of Total Investments)             
1,000    Castaic Lake Water Agency, California, Certificates of Participation, Series 2006C, 5.000%,    8/16 at 100.00    AA–    979,550 
     8/01/36 – MBIA Insured             
750    Fortuna Public Finance Authority, California, Water Revenue Bonds, Series 2006, 5.000%,    10/16 at 100.00    AAA    721,838 
     10/01/36 – FSA Insured             
215    Healdsburg Public Financing Authority, California, Wastewater Revenue Bonds, Series 2006,    4/16 at 100.00    AA–    200,565 
     5.000%, 4/01/36 – MBIA Insured             
770    Manteca Financing Authority, California, Sewerage Revenue Bonds, Series 2003B, 5.000%,    12/13 at 100.00    A2    771,317 
     12/01/33 – MBIA Insured             
170    Marina Coast Water District, California, Enterprise Certificate of Participation, Series 2006,    6/16 at 100.00    AA–    158,817 
     5.000%, 6/01/31 – MBIA Insured             
    San Diego Public Facilities Financing Authority, California, Subordinate Lien Water Revenue             
    Bonds, Series 2002:             
3,000     5.000%, 8/01/22 – MBIA Insured    8/12 at 100.00    AA–    3,036,900 
2,500     5.000%, 8/01/23 – MBIA Insured    8/12 at 100.00    AA–    2,525,375 
1,180    South Feather Water and Power Agency, California, Water Revenue Certificates of Participation,    4/13 at 100.00    A    1,083,110 
     Solar Photovoltaic Project, Series 2003, 5.375%, 4/01/24             
1,600    Sunnyvale Financing Authority, California, Water and Wastewater Revenue Bonds, Series 2001,    10/11 at 100.00    AAA    1,606,192 
     5.000%, 10/01/26 – AMBAC Insured             
11,185    Total Water and Sewer            11,083,664 
$     113,657    Total Long-Term Investments (cost $112,270,201) – 137.9%            108,437,195 
    Short-Term Investments – 4.5% (3.1% of Total Investments)             
$         3,500    California, General Obligation Bonds, Variable Rate Demand Obligations, Series 2003C-1,    6/09 at 100.00    A-1    3,500,000 
     0.150%, 5/01/33 (5)             
    Total Short-Term Investments (cost $3,500,000)            3,500,000 
    Total Investments (cost $115,770,201) – 142.4%            111,937,195 
    Variable Rate Demand Preferred Shares, at Liquidation Value – (45.2%) (6)            (35,500,000)
    Other Assets Less Liabilities – 2.8%            2,164,852 
    Net Assets Applicable to Common Shares – 100%          $  78,602,047 

Fair Value Measurements

During the current fiscal period, the Fund adopted the provisions of Statement of Financial Accounting Standards No. 157 (SFAS No.157) “Fair Value Measurements.” SFAS No. 157 defines fair value, establishes a framework for measuring fair value in generally accepted accounting principles and expands disclosure about fair value measurements. In determining the value of the Fund’s investments various inputs are used. These inputs are summarized in the three broad levels listed below:

Level 1 – Quoted prices in active markets for identical securities.

Level 2 – Other significant observable inputs (including quoted prices for similar securities, interest rates, prepayment speeds, credit risk, etc.).

Level 3 – Significant unobservable inputs (including management’s assumptions in determining the fair value of investments).

The inputs or methodology used for valuing securities are not an indication of the risk associated with investing in those securities. The following is a summary of the Fund’s fair value measurements as of May 31, 2009:

    Level 1    Level 2    Level 3    Total 
Investments    $ —    $111,937,195    $ —    $111,937,195 

Income Tax Information

The following information is presented on an income tax basis. Differences between amounts for financial statement and federal income tax purposes are primarily due to timing differences in recognizing taxable market discount, timing differences in recognizing certain gains and losses on investment transactions and the treatment of investments in inverse floating rate transactions subject to Statement of Financial Accounting Standards No. 140 (SFAS No. 140), if any. To the extent that differences arise that are permanent in nature, such amounts are reclassified within the capital accounts on the Statement of Assets and Liabilities presented in the annual report, based on their federal tax basis treatment; temporary differences do not require reclassification. Temporary and permanent differences do not impact the net asset value of the Fund.

At May 31, 2009, the cost of investments was $115,748,505.

Gross unrealized appreciation and gross unrealized depreciation of investments at May 31, 2009, were as follows:

Gross unrealized:     
  Appreciation    $ 3,283,287 
  Depreciation    (7,094,597)
Net unrealized appreciation (depreciation) of investments    $(3,811,310)

    At least 80% of the Fund’s net assets (including net assets attributable to Variable Rate Demand Preferred 
    shares) are invested in municipal securities that guarantee the timely payment of principal and interest. 
(1)    All percentages shown in the Portfolio of Investments are based on net assets applicable to Common 
    shares unless otherwise noted. 
(2)    Optional Call Provisions: Dates (month and year) and prices of the earliest optional call or redemption. 
    There may be other call provisions at varying prices at later dates. Certain mortgage-backed securities 
    may be subject to periodic principal paydowns. 
(3)    Ratings: Using the higher of Standard & Poor’s Group (“Standard & Poor’s”) or Moody’s Investor Service, 
    Inc. (“Moody’s”) rating. Ratings below BBB by Standard & Poor’s or Baa by Moody’s are considered to be 
    below investment grade. 
    The Portfolio of Investments may reflect the ratings on certain bonds whose insurer has experienced 
    downgrades as of the end of the reporting period. Subsequent to the reporting period, and during the 
    period this Portfolio of Investments was prepared, there may have been reductions to the ratings of 
    certain bonds resulting from changes to the ratings of the underlying insurers both during the period and 
    after period end. Such reductions would likely reduce the effective rating of many of the bonds insured 
    by that insurer or insurers presented at period end. 
(4)    Backed by an escrow or trust containing sufficient U.S. Government or U.S. Government agency securities 
    which ensure the timely payment of principal and interest. Such investments are normally considered to 
    be equivalent to AAA rated securities. 
(5)    Investment has a maturity of more than one year, but has variable rate and demand features which 
    qualify it as a short-term investment. The rate disclosed is that in effect at the end of the reporting 
    period. This rate changes periodically based on market conditions or a specified market index. 
(6)    Variable Rate Demand Preferred Shares, at Liquidation Value as a percentage of Total Investments is 31.7%. 
(IF)    Inverse floating rate investment. 

Item 2. Controls and Procedures.

  1. The registrant's principal executive and principal financial officers, or persons performing similar functions, have concluded that the registrant's disclosure controls and procedures (as defined in Rule 30a-3(c) under the Investment Company Act of 1940, as amended (the "1940 Act") (17 CFR 270.30a-3(c))) are effective, as of a date within 90 days of the filing date of this report that includes the disclosure required by this paragraph, based on their evaluation of the controls and procedures required by Rule 30a-3(b) under the 1940 Act (17 CFR 270.30a-3(b)) and Rule 13a-15(b) or 15d-15(b) under the Securities Exchange Act of 1934 (17 CFR 240.13a-15(b) or 240.15d-15(b)).
  2. There were no changes in the registrant's internal control over financial reporting (as defined in Rule 30a-3(d) under the 1940 Act (17 CFR 270.30a-3(d)) that occurred during the registrant's last fiscal quarter that have materially affected, or are reasonably likely to materially affect, the registrant's internal control over financial reporting.

Item 3. Exhibits.

File as exhibits as part of this Form a separate certification for each principal executive officer and principal financial officer of the registrant as required by Rule 30a-2(a) under the 1940 Act (17 CFR 270.30a-2(a)), exactly as set forth below: See EX-99 CERT attached hereto.


SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

(Registrant)         Nuveen Insured California Tax-Free Advantage Municipal Fund         

By (Signature and Title)          /s/ Kevin J. McCarthy                    
                                                  Kevin J. McCarthy
                                                  Vice President and Secretary

Date         July 30, 2009        

Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, this report has been signed below by the following persons on behalf of the registrant and in the capacities and on the dates indicated.

By (Signature and Title)         /s/ Gifford R. Zimmerman                    
                                                 Gifford R. Zimmerman
                                                 Chief Administrative Officer (principal executive officer) 

Date         July 30, 2009        

By (Signature and Title)         /s/ Stephen D. Foy                              
                                                 Stephen D. Foy
                                                 Vice President and Controller (principal financial officer) 

Date        July 30, 2009