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         811-09449         

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


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


Jessica R. Droeger—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:            8/31          

Date of reporting period:          5/31/06         

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 Dividend Advantage Municipal Fund (NKL)             
                           May 31, 2006             
        Optional         
Principal        Call         
Amount (000)    Description (1)    Provisions (2)    Ratings (3)    Value 
    Consumer Staples – 2.3% (1.6% of Total Investments)             
$          4,500    Golden State Tobacco Securitization Corporation, California, Tobacco Settlement Asset-Backed    6/13 at 100.00    BBB   $   5,384,655 
     Revenue Bonds, Series 2003A-2, 7.900%, 6/01/42             
    Education and Civic Organizations – 8.8% (5.9% of Total Investments)             
1,675    California Educational Facilities Authority, Revenue Bonds, University of San Diego, Series    10/12 at 100.00    A2    1,725,317 
     2002A, 5.250%, 10/01/30             
9,000    California State University, Systemwide Revenue Bonds, Series 2002A, 5.125%, 11/01/26 –    11/12 at 100.00    AAA    9,363,510 
     AMBAC Insured             
9,000    University of California, Revenue Bonds, Multiple Purpose Projects, Series 2000K, 5.300%,    9/08 at 101.00    AA    9,225,630 
     9/01/30             
19,675    Total Education and Civic Organizations            20,314,457 
    Health Care – 5.6% (3.8% of Total Investments)             
5,000    ABAG Finance Authority for Non-Profit Corporations, California, Cal-Mortgage Insured Revenue    4/12 at 100.00    A    5,276,750 
     Bonds, Sansum-Santa Barbara Medical Foundation Clinic, Series 2002A, 5.600%, 4/01/26             
2,815    California Health Facilities Financing Authority, Revenue Bonds, Lucile Salter Packard    8/13 at 100.00    AAA    2,922,561 
     Children’s Hospital, Series 2003C, 5.000%, 8/15/20 – AMBAC Insured             
1,090    California State Public Works Board, Revenue Bonds, University of California – Davis Medical    11/14 at 100.00    AAA    1,131,278 
     Center, Series 2004II-A, 5.000%, 11/01/21 – MBIA Insured             
3,380    Rancho Mirage Joint Powers Financing Authority, California, Revenue Bonds, Eisenhower Medical    7/14 at 100.00    A3    3,665,678 
     Center, Series 2004, 5.875%, 7/01/26             
12,285    Total Health Care            12,996,267 
    Housing/Multifamily – 1.3% (0.8% of Total Investments)             
1,000    California Statewide Community Development Authority, Student Housing Revenue Bonds, EAH –    8/12 at 100.00    A    1,040,100 
     Irvine East Campus Apartments, LLC Project, Series 2002A, 5.500%, 8/01/22 – ACA Insured             
1,905    Los Angeles, California, GNMA Mortgage-Backed Securities Program Multifamily Housing    7/11 at 102.00    AAA    1,983,696 
     Revenue Bonds, Park Plaza West Senior Apartments, Series 2001B, 5.300%, 1/20/21 (Alternative             
     Minimum Tax)             
2,905    Total Housing/Multifamily            3,023,796 
    Industrials – 1.4% (0.8% of Total Investments)             
3,000    California Pollution Control Financing Authority, Solid Waste Disposal Revenue Bonds, Republic    No Opt. Call    BBB+    3,122,280 
     Services Inc., Series 2002C, 5.250%, 6/01/23 (Mandatory put 12/01/17) (Alternative Minimum Tax)             
    Long-Term Care – 3.5% (2.4% of Total Investments)             
3,000    ABAG Finance Authority for Non-Profit Corporations, California, Insured Senior Living Revenue    11/12 at 100.00    A    3,099,990 
     Bonds, Odd Fellows Home of California, Series 2003A, 5.200%, 11/15/22             
5,000    California Statewide Community Development Authority, Revenue Bonds, Jewish Home for the    11/13 at 100.00    A    5,139,200 
     Aging, Series 2003, 5.000%, 11/15/18             
8,000    Total Long-Term Care            8,239,190 
    Tax Obligation/General – 31.9% (21.4% of Total Investments)             
5,920    Cajon Valley Union School District, San Diego County, California, General Obligation Bonds,    8/10 at 102.00    AAA    6,108,256 
     Series 2002B, 5.125%, 8/01/32 – MBIA Insured             
2,900    California, General Obligation Bonds, Series 2003, 5.000%, 2/01/21    8/13 at 100.00    A    2,995,874 
1,750    California, General Obligation Bonds, Series 2004, 5.125%, 2/01/27    2/14 at 100.00    A    1,810,392 
8,250    California, General Obligation Refunding Bonds, Series 2002, 5.000%, 2/01/22 – MBIA Insured    2/12 at 100.00    AAA    8,497,500 
    Compton Community College District, Los Angeles County, California, General Obligation Bonds,             
    Series 2004A:             
1,315     5.250%, 7/01/22 – MBIA Insured    7/14 at 100.00    AAA    1,410,627 
2,560     5.250%, 7/01/23 – MBIA Insured    7/14 at 100.00    AAA    2,744,346 
2,415    El Monte Union High School District, Los Angeles County, California, General Obligation Bonds,    6/13 at 100.00    AAA    2,483,175 
     Series 2003A, 5.000%, 6/01/28 – FSA Insured             
10,000    Fremont Unified School District, Alameda County, California, General Obligation Bonds, Series    8/12 at 101.00    AAA    10,362,300 
     2002A, 5.000%, 8/01/25 – FGIC Insured             
5,000    Los Angeles Unified School District, California, General Obligation Bonds, Series 2002E,    7/12 at 100.00    AAA    5,202,800 
     5.125%, 1/01/27 – MBIA Insured             
    Los Angeles Unified School District, California, General Obligation Bonds, Series 2003A:             
3,700     5.000%, 7/01/22 – FSA Insured    7/13 at 100.00    AAA    3,849,924 
3,500     5.000%, 1/01/28 – MBIA Insured    7/13 at 100.00    AAA    3,616,585 
1,500    Madera Unified School District, Madera County, California, General Obligation Bonds, Series    8/12 at 100.00    AAA    1,539,495 
     2002, 5.000%, 8/01/28 – FSA Insured             
2,500    Oakland Unified School District, Alameda County, California, General Obligation Bonds, Series    8/12 at 100.00    AAA    2,653,725 
     2002, 5.250%, 8/01/21 – FGIC Insured             
    Oakland Unified School District, Alameda County, California, General Obligation Bonds,             
    Series 2005:             
505     5.000%, 8/01/25 – MBIA Insured    8/15 at 100.00    AAA    525,109 
530     5.000%, 8/01/26 – MBIA Insured    8/15 at 100.00    AAA    549,896 
3,250    San Diego Unified School District, San Diego County, California, General Obligation Bonds,    7/11 at 102.00    AAA    3,459,300 
     Election of 1998, Series 2001C, 5.000%, 7/01/22 – FSA Insured             
1,160    San Gabriel Unified School District, Los Angeles County, California, General Obligation Bonds,    8/15 at 100.00    AAA    1,215,982 
     Series 2005, 5.000%, 8/01/22 – FSA Insured             
    San Jose-Evergreen Community College District, Santa Clara County, California, General             
    Obligation Bonds, Series 2005A:             
395     5.000%, 9/01/25 – MBIA Insured    9/15 at 100.00    AAA    412,060 
575     5.000%, 9/01/27 – MBIA Insured    9/15 at 100.00    AAA    597,178 
3,500    San Mateo County Community College District, California, General Obligation Bonds, Series    9/12 at 100.00    AAA    3,602,830 
     2002A, 5.000%, 9/01/26 – FGIC Insured             
10,000    Vista Unified School District, San Diego County, California, General Obligation Bonds, Series    8/12 at 100.00    AAA    10,384,900 
     2002A, 5.000%, 8/01/23 – FSA Insured             
71,225    Total Tax Obligation/General            74,022,254 
    Tax Obligation/Limited – 42.3% (28.4% of Total Investments)             
1,450    Baldwin Park Public Financing Authority, California, Sales Tax and Tax Allocation Bonds,    8/13 at 102.00    BBB    1,505,158 
     Puente Merced Redevelopment Project, Series 2003, 5.250%, 8/01/21             
6,895    Brea and Olinda Unified School District, Orange County, California, Certificates of    8/11 at 101.00    AAA    7,137,497 
     Participation Refunding, Series 2002A, 5.125%, 8/01/26 – FSA Insured             
2,290    Burbank Public Financing Authority, California, Revenue Refunding Bonds, Golden State    12/13 at 100.00    AAA    2,438,026 
     Redevelopment Project, Series 2003A, 5.250%, 12/01/19 – AMBAC Insured             
2,200    California Infrastructure Economic Development Bank, Los Angeles County, Revenue Bonds,    9/13 at 101.00    AAA    2,268,068 
     Department of Public Social Services, Series 2003, 5.000%, 9/01/28 – AMBAC Insured             
3,100    California State Public Works Board, Lease Revenue Bonds, Department of Health Services,    11/15 at 100.00    AAA    3,183,049 
     Richmond Lab, Series 2005B, 5.000%, 11/01/30 – XLCA Insured             
7,035    Corona-Norco Unified School District, Riverside County, California, Special Tax Bonds,    9/13 at 100.00    AAA    7,230,362 
     Community Facilities District 98-1, Series 2003, 5.000%, 9/01/28 – MBIA Insured             
3,145    Culver City Redevelopment Agency, California, Tax Allocation Revenue Bonds, Redevelopment    5/11 at 101.00    AAA    3,255,075 
     Project, Series 2002A, 5.125%, 11/01/25 – MBIA Insured             
8,720    El Monte, California, Senior Lien Certificates of Participation, Department of Public Services    1/11 at 100.00    AAA    8,925,618 
     Facility Phase II, Series 2001, 5.000%, 1/01/21 – AMBAC Insured             
4,000    Folsom Public Financing Authority, California, Special Tax Revenue Bonds, Series 2004A,    9/12 at 102.00    AAA    4,157,240 
     5.000%, 9/01/21 – AMBAC Insured             
355    Hesperia Community Redevelopment Agency, California, Tax Allocation Bonds, Series 2005A,    9/15 at 100.00    AAA    371,156 
     5.000%, 9/01/20 – XLCA Insured             
2,115    Inglewood Redevelopment Agency, California, Tax Allocation Refunding Bonds, Merged Area    No Opt. Call    AAA    2,311,653 
     Redevelopment Project, Series 1998A, 5.250%, 5/01/23 – AMBAC Insured             
3,500    La Quinta Redevelopment Agency, California, Tax Allocation Bonds, Redevelopment Project Area    9/11 at 102.00    AAA    3,608,990 
     1, Series 2001, 5.100%, 9/01/31 – AMBAC Insured             
3,400    La Quinta Redevelopment Agency, California, Tax Allocation Bonds, Redevelopment Project Area    9/12 at 102.00    AAA    3,536,068 
     1, Series 2002, 5.000%, 9/01/22 – AMBAC Insured             
4,690    Los Angeles County Metropolitan Transportation Authority, California, Proposition C Second    7/08 at 101.00    AAA    4,828,730 
     Senior Lien Sales Tax Revenue Refunding Bonds, Series 1998A, 5.000%, 7/01/23 – AMBAC Insured             
1,460    Los Angeles, California, Certificates of Participation, Municipal Improvement Corporation,    6/13 at 100.00    AAA    1,492,427 
     Series 2003AW, 5.000%, 6/01/33 – AMBAC Insured             
7,000    Los Angeles, California, Certificates of Participation, Series 2002, 5.200%, 4/01/27 –    4/12 at 100.00    AAA    7,269,990 
     AMBAC Insured             
8,470    Ontario Redevelopment Financing Authority, California, Lease Revenue Bonds, Capital Projects,    8/11 at 101.00    AAA    8,839,631 
     Series 2001, 5.200%, 8/01/29 – AMBAC Insured             
5,000    Palm Desert Financing Authority, California, Tax Allocation Revenue Refunding Bonds, Project    4/12 at 102.00    AAA    5,164,850 
     Area 1, Series 2002, 5.000%, 4/01/25 – MBIA Insured             
405    Rialto Redevelopment Agency, California, Tax Allocation Bonds, Merged Project Area, Series    9/15 at 100.00    AAA    414,153 
     2005A, 5.000%, 9/01/35 – XLCA Insured             
845    Riverside County Public Financing Authority, California, Tax Allocation Bonds, Multiple    10/15 at 100.00    AAA    864,241 
     Projects, Series 2005A, 5.000%, 10/01/35 – XLCA Insured             
4,475    Riverside County, California, Asset Leasing Corporate Leasehold Revenue Bonds, Riverside    6/12 at 101.00    AAA    4,662,950 
     County Hospital Project, Series 1997B, 5.000%, 6/01/19 – MBIA Insured             
3,175    San Buenaventura, California, Certificates of Participation, Series 2001C, 5.250%, 2/01/31 –    2/11 at 101.00    AAA    3,305,937 
     AMBAC Insured             
3,730    San Diego Redevelopment Agency, California, Subordinate Lien Tax Increment and Parking Revenue    9/09 at 101.00    Baa2    3,831,829 
     Bonds, Centre City Project, Series 2003B, 5.250%, 9/01/26             
4,000    San Jose Financing Authority, California, Lease Revenue Refunding Bonds, Convention Center    9/11 at 100.00    AAA    4,194,440 
     Project, Series 2001F, 5.000%, 9/01/19 – MBIA Insured             
1,000    Shasta Joint Powers Financing Authority, California, Lease Revenue Bonds, County    4/13 at 100.00    AAA    1,054,760 
     Administration Building Project, Series 2003A, 5.250%, 4/01/23 – MBIA Insured             
2,160    Temecula Redevelopment Agency, California, Tax Allocation Revenue Bonds, Redevelopment    8/08 at 102.00    AAA    2,238,862 
     Project 1, Series 2002, 5.125%, 8/01/27 – MBIA Insured             
94,615    Total Tax Obligation/Limited            98,090,760 
    Transportation – 4.8% (3.3% of Total Investments)             
7,500    Foothill/Eastern Transportation Corridor Agency, California, Toll Road Revenue Refunding    1/14 at 101.00    BBB–    6,525,000 
     Bonds, Series 1999, 0.000%, 1/15/29             
    San Francisco Airports Commission, California, Revenue Bonds, San Francisco International             
    Airport, Second Series 2003, Issue 29A:             
2,185     5.250%, 5/01/16 – FGIC Insured (Alternative Minimum Tax)    5/13 at 100.00    AAA    2,304,629 
2,300     5.250%, 5/01/17 – FGIC Insured (Alternative Minimum Tax)    5/13 at 100.00    AAA    2,417,507 
11,985    Total Transportation            11,247,136 
    U.S. Guaranteed – 12.5% (8.4% of Total Investments) (4)             
6,000    California Department of Water Resources, Power Supply Revenue Bonds, Series 2002A, 5.125%,    5/12 at 101.00    Aaa    6,489,420 
     5/01/18 (Pre-refunded 5/01/12)             
    California Health Facilities Financing Authority, Revenue Bonds, Cedars-Sinai Medical Center,             
    Series 1999A:             
2,500     6.125%, 12/01/30 (Pre-refunded 12/01/09)    12/09 at 101.00    A3 (4)    2,720,600 
1,000     6.250%, 12/01/34 (Pre-refunded 12/01/09)    12/09 at 101.00    A3 (4)    1,092,310 
2,250    California Infrastructure Economic Development Bank, First Lien Revenue Bonds, San Francisco    1/28 at 100.00    AAA    2,402,618 
     Bay Area Toll Bridge, Series 2003A, 5.000%, 7/01/36 (Pre-refunded 1/01/28) – AMBAC Insured             
    Fresno Unified School District, Fresno County, California, General Obligation Bonds,             
    Series 2002B:             
1,135     5.125%, 8/01/23 – FGIC Insured (ETM)    8/10 at 102.00    AAA    1,201,216 
1,190     5.125%, 8/01/24 – FGIC Insured (ETM)    8/10 at 102.00    AAA    1,259,425 
1,245     5.125%, 8/01/25 – FGIC Insured (ETM)    8/10 at 102.00    AAA    1,321,094 
1,255     5.125%, 8/01/26 – FGIC Insured (ETM)    8/10 at 102.00    AAA    1,320,975 
2,070    Fresno Unified School District, Fresno County, California, General Obligation Bonds, Series    8/10 at 102.00    AAA    2,178,820 
     2002G, 5.125%, 8/01/26 – FSA Insured (ETM)             
3,000    Peralta Community College District, Alameda County, California, General Obligation Bonds,    8/09 at 102.00    AAA    3,179,190 
     Election of 2000, Series 2001A, 5.000%, 8/01/31 (Pre-refunded 8/01/09) – FGIC Insured             
2,980    Santa Clarita Community College District, Los Angeles County, California, General Obligation    8/11 at 101.00    AAA    3,207,225 
     Bonds, Series 2002, 5.125%, 8/01/26 (Pre-refunded 8/01/11) – FGIC Insured             
2,460    Vacaville Unified School District, Solano County, California, General Obligation Bonds, Series    8/11 at 101.00    AAA    2,633,209 
     2002, 5.000%, 8/01/26 (Pre-refunded 8/01/11) – FSA Insured             
27,085    Total U.S. Guaranteed            29,006,102 
    Utilities – 17.1% (11.5% of Total Investments)             
9,000    Anaheim Public Finance Authority, California, Revenue Bonds, Electric System Distribution    10/12 at 100.00    AAA    9,236,070 
     Facilities, Series 2002A, 5.000%, 10/01/27 – FSA Insured             
10,000    California Pollution Control Financing Authority, Remarketed Revenue Bonds, Pacific Gas and    4/11 at 102.00    AAA    10,563,897 
     Electric Company, Series 1996A, 5.350%, 12/01/16 – MBIA Insured (Alternative Minimum Tax)             
3,000    Los Angeles Department of Water and Power, California, Power System Revenue Bonds, Series    7/11 at 100.00    AAA    3,159,570 
     2001A-1, 5.250%, 7/01/21 – FSA Insured             
775    Los Angeles Department of Water and Power, California, Power System Revenue Bonds, Series    7/13 at 100.00    AAA    805,109 
     2003A-2, 5.000%, 7/01/21 – MBIA Insured             
830    Merced Irrigation District, California, Electric System Revenue Bonds, Series 2005, 5.125%,    9/15 at 100.00    AAA    860,884 
     9/01/31 – XLCA Insured             
6,000    Northern California Power Agency, Revenue Refunding Bonds, Hydroelectric Project 1, Series    7/08 at 101.00    AAA    6,196,860 
     1998A, 5.200%, 7/01/32 – MBIA Insured             
3,000    Sacramento Municipal Utility District, California, Electric Revenue Bonds, Series 2001N,    8/11 at 100.00    AAA    3,071,520 
     5.000%, 8/15/28 – MBIA Insured             
5,630    Southern California Public Power Authority, Subordinate Revenue Refunding Bonds, Transmission    7/12 at 100.00    AAA    5,750,538 
     Project, Series 2002A, 4.750%, 7/01/19 – FSA Insured             
38,235    Total Utilities            39,644,448 
    Water and Sewer – 17.4% (11.7% of Total Investments)             
3,000    California Department of Water Resources, Water System Revenue Bonds, Central Valley Project,    12/12 at 100.00    AAA    3,166,950 
     Series 2002X, 5.150%, 12/01/23 – FGIC Insured             
6,100    East Bay Municipal Utility District, Alameda and Contra Costa Counties, California, Water    6/11 at 100.00    AAA    6,277,022 
     System Subordinated Revenue Bonds, Series 2001, 5.000%, 6/01/26 – MBIA Insured             
9,000    Eastern Municipal Water District, California, Water and Sewerage System Revenue Certificates    7/11 at 100.00    AAA    9,159,120 
     of Participation, Series 2001B, 5.000%, 7/01/30 – FGIC Insured             
570    Healdsburg Public Financing Authority, California, Wastewater Revenue Bonds, Series 2006,    4/16 at 100.00    AAA    587,607 
     5.000%, 4/01/36 (WI/DD, Settling 6/06/06) – MBIA Insured             
4,500    Los Angeles County Sanitation Districts Financing Authority, California, Senior Revenue Bonds,    10/13 at 100.00    AAA    4,675,140 
     Capital Projects, Series 2003A, 5.000%, 10/01/23 – FSA Insured             
1,140    Los Angeles Department of Water and Power, California, Waterworks Revenue Bonds, Series    7/16 at 100.00    AAA    1,187,162 
     2006A-2, 5.000%, 7/01/27 – AMBAC Insured             
3,050    Manteca Financing Authority, California, Sewerage Revenue Bonds, Series 2003B, 5.000%,    12/13 at 100.00    Aaa    3,059,455 
     12/01/33 – MBIA Insured             
9,185    Orange County Sanitation District, California, Certificates of Participation, Series 2003,    8/13 at 100.00    AAA    9,414,992 
     5.000%, 2/01/33 – FGIC Insured             
    Semitropic Water Storage District, Kern County, California, Water Banking Revenue Bonds,             
    Series 2004A:             
1,315     5.500%, 12/01/20 – XLCA Insured    12/14 at 100.00    AAA    1,431,733 
1,415     5.500%, 12/01/21 – XLCA Insured    12/14 at 100.00    AAA    1,539,562 
39,275    Total Water and Sewer            40,498,743 
$      332,785    Total Investments (cost $328,917,906) – 148.9%            345,590,088 
    Other Assets Less Liabilities – 1.9%            4,508,262 
    Preferred Shares, at Liquidation Value – (50.8)%            (118,000,000) 
    Net Assets Applicable to Common Shares – 100%           $   232,098,350 

    At least 80% of the Fund’s net assets (including net assets attributable to Preferred shares) are invested 
    in municipal securities that are either covered by Original Issue Insurance, Secondary Market Insurance 
    or Portfolio Insurance which ensures the timely payment of principal and interest. Up to 20% of the Fund’s 
    net assets (including net assets attributable to Preferred shares) may be invested in municipal securities 
    that are (i) either backed by an escrow or trust containing sufficient U.S. Government or U.S. Government 
    agency securities (also ensuring the timely payment of principal and interest), or (ii) rated, at the time of 
    investment, within the four highest grades (Baa or BBB or better by Moody’s, S&P or Fitch) or unrated but 
    judged to be of comparable quality by the Adviser. 
(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 or Moody’s rating. Ratings below BBB by Standard & Poor’s 
    Group or Baa by Moody’s Investor Service, Inc. are considered to be below investment grade. 
(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. 
(ETM)    Escrowed to maturity. 
WI/DD    Purchased on a when-issued or delayed delivery basis. 

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 the treatment of paydown gains and losses, timing differences in recognizing taxable market discount and timing differences in recognizing certain gains and losses on investment transactions.

At May 31, 2006, the cost of investments was $330,962,264.

Gross unrealized appreciation and gross unrealized depreciation of investments at May 31, 2006, were as follows:

Gross unrealized:     
  Appreciation    $16,969,083 
  Depreciation    (2,341,259) 
Net unrealized appreciation (depreciation) of investments    $14,627,824 

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: 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 Dividend Advantage Municipal Fund        

By (Signature and Title)*          /s/ Jessica R. Droeger                     
                                                    Jessica R. Droeger
                                                    Vice President and Secretary

Date         July 28, 2006        

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 28, 2006        

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

Date        July 28, 2006        

* Print the name and title of each signing officer under his or her signature.