UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

FORM N-Q

QUARTERLY SCHEDULE OF PORTFOLIO HOLDINGS OF REGISTERED
MANAGEMENT INVESTMENT COMPANY

Investment Company Act file number:__811-21181______

_______BlackRock Municipal 2020 Term Trust_______
(Exact name of registrant as specified in charter)

100 Bellevue Parkway, Wilmington, DE 
19809 
(Address of principal executive offices) 
(Zip code) 

Robert S. Kapito, President
BlackRock Municipal 2020 Term Trust
40 East 52nd Street, New York, NY 10022
(Name and address of agent for service)

Registrant's telephone number, including area code:_888-825-2257                              

Date of fiscal year end:___December 31, 2006
Date of reporting period:__March 31, 2006

Item 1. Schedule of Investments.

The Registrant’s unaudited schedule of investments as of the close of the reporting period pursuant to Rule 30b1-5 under the Investment Company Act of 1940 is as follows:

PORTFOLIO OF INVESTMENTS
MARCH 31, 2006 (unaudited)
BlackRock Municipal 2020 Term Trust (BKK)

  Principal          
    Amount     Option Call    
Rating1   (000)   Description Provisions2   Value  
      LONG-TERM INVESTMENTS—154.1%      
        California—24.5%      
A   $12,000   California GO, 5.00%, 11/01/22 11/13 @ 100   $ 12,466,920  
        Foothill/Eastern Corridor Agcy. Toll Rd. Cap. Apprec. RB,      
BBB   12,500         Zero Coupon, 1/15/21 01/10 @ 53.346   5,270,625
BBB   10,000         Zero Coupon, 1/15/22 01/10 @ 50.177   3,966,900
        Golden St. Tobacco Sec. Corp. RB,      
BBB   3,000         Ser. A-1, 6.625%, 6/01/40 06/13 @ 100   3,335,790  
BBB   12,010         Ser. A-1, 6.75%, 6/01/39 06/13 @ 100   13,506,566  
BBB   975         Ser. A-3, 7.875%, 6/01/42 06/13 @ 100   1,163,887  
BBB   1,470         Ser. A-5, 7.875%, 6/01/42 06/13 @ 100   1,754,783  
AAA   20,000 3        Ser. B, 5.375%, 6/01/10 N/A   21,302,200  
BBB+   7,000   Poll. Ctrl. Fin. Auth. Sld. Wst. Disp. RB, Republic Svcs., Inc. Proj., Ser. C, 5.25%, 6/01/23 No Opt. Call   7,348,460  
BBB   3,000   Poll. Ctrl. Sld. Wst. Mgmt. RB, Ser. A, 5.125%, 7/01/31 03/06 @ 100   3,113,280  
AAA   6,865   Riverside Cnty. RB, Riverside Cnty. Hosp. Proj., Zero Coupon, 6/01/25, MBIA No Opt. Call   2,695,679  
              75,925,090  
        Colorado—1.7%      
AAA   4,500   E-470 Pub. Hwy. Auth. Cap. Apprec. RB, Ser. B, Zero Coupon, 9/01/22, MBIA No Opt. Call   2,116,890  
Baa2   3,000   Park Creek Met. Dist. Co. RB, 5.25%, 12/01/25 12/15 @ 101   3,057,930  
              5,174,820  
        District of Columbia—5.2%      
        RB, Friendship Pub. Charter Sch., Inc. Proj.,      
A   3,320         5.00%, 6/01/23, ACA 06/14 @ 100   3,324,183  
A   2,680         5.75%, 6/01/18, ACA 06/14 @ 100   2,863,017  
AAA   5,000   Met. Arpts. Auth. Arpt. Sys. RB, Ser. C-2, 5.00%, 10/01/24, FSA 10/14 @ 100   5,149,850  
BBB   4,215   Tobacco Settlement Fin. Corp. RB, 6.50%, 5/15/33 No Opt. Call   4,793,214  
              16,130,264  
        Florida—15.0%      
NR   830   Baywinds Cmnty. Dev. Dist. RB, Ser. B, 4.90%, 5/01/12 No Opt. Call   830,000  
NR   4,860   Bellago Edl. Facs. Benefit Dist. SA, Ser. A, 5.85%, 5/01/22 05/14 @ 100   4,947,772  
Baa2   1,500 3  Cap. Trust Agcy. Multi-Fam. Hsg. RB, American Oppty. Proj., Ser. A, 5.75%, 6/01/23 N/A   1,443,840  
NR   3,000   CFM Cmnty. Dev. Dist. Cap. Impvt. RB, Ser. B, 5.875%, 5/01/14 No Opt. Call   3,059,010  
NR   4,445   Grand Hampton Cmnty. Dev. Dist. Cap. Impvt. RB, 6.10%, 5/01/24 05/13 @ 101   4,596,841  
NR   4,025   Habitat Cmnty. Dev. Dist. SA, 5.80%, 5/01/25 05/14 @ 101   4,017,554  
BB+   5,475   Miami Beach Hlth. Facs. Auth. RB, Mt. Sinai Med. Ctr. Proj., 6.75%, 11/15/21 11/14 @ 100   6,112,509  
NR   4,525   Middle Vlg. Cmnty. Dev. Dist. SA, Ser. A, 5.80%, 5/01/22 05/13 @ 100   4,634,731  
NR   1,000   Pine Islands Cmnty. Dev. Dist. Util. Sys. RB, 5.30%, 11/01/10 No Opt. Call   990,260  
NR   6,080   Stevens Plantation Cmnty. Dist. SA, Ser. B, 6.375%, 5/01/13 No Opt. Call   6,186,217  
NR   3,480   Vlg. Cmnty. Dev. Dist. Assmt., No. 5 SA, Ser. A, 6.00%, 5/01/22 05/13 @ 101   3,624,803  
NR   5,810   Westchester Cmnty. Dev. Dist. No. 1 SA, 6.00%, 5/01/23 05/13 @ 101   6,013,931  
              46,457,468  
        Georgia—1.6%      
BBB   2,500   Milledgeville Baldwin Cnty. Dev. Auth. RB, Georgia Coll. & St. Univ. Fndtn. Proj., 5.50%, 9/01/24
09/14 @ 101
 
2,617,900
BBB   2,350   Richmond Cnty. Dev. Auth. Env. Impvt. RB, 5.75%, 11/01/27
11/13 @ 100
  2,418,103  
              5,036,003  
        Illinois—12.4%      
NR   2,155 4  Centerpoint Intermodal Ctr. Prog. Trust TA, Ser. A, 8.00%, 6/15/23 No Opt. Call   2,161,228  
        Chicago O'Hare Intl. Arpt. RB,
AAA   5,000         Ser. A, 5.00%, 1/01/21, AMBAC 01/16 @ 100   5,231,200  
AAA   7,000         Ser. A, 5.00%, 1/01/22, AMBAC 01/16 @ 100   7,312,410  
Baa1   5,000   Dev. Fin. Auth. RB, Depaul Univ. Proj., Ser. C, 5.25%, 10/01/24 10/14 @ 100   5,254,950  
AA+   4,800   Edl. Fac. Auth. RB, Northwestern Univ. Proj., 5.00%, 12/01/21 12/13 @ 100   5,001,024  
        Fin. Auth. Student Hsg. RB, MJH Ed. Asst. Living Proj.,
Baa2   2,725         Ser. A, 5.00%, 6/01/24 06/14 @ 100   2,695,543  
Baa2   3,250         Ser. A, 5.50%, 6/01/19 06/14 @ 100   3,389,230  
Baa3   1,075         Ser. B, 5.00%, 6/01/24 06/14 @ 100   1,049,028  
AAA   13,455   Met. Pier & Expo. Auth. Ded. RB, McCormick Place Expansion Proj.,      
              Ser. A, Zero Coupon, 6/15/22, MBIA No Opt. Call   6,493,248  
              38,587,861  
   

1

BlackRock Municipal 2020 Term Trust (BKK) (continued)

  Principal          
    Amount     Option Call    
Rating1   (000)   Description Provisions2   Value  
      Indiana—5.0%      
BBB   $10,000   Indianapolis Arpt. Auth. RB, FedEx Corp. Proj., 5.10%, 1/15/17 No Opt. Call   $ 10,317,400  
NR   5,140   Vincennes Econ. Dev. RB, Southwest Indiana Regl. Youth Proj., 6.25%, 1/01/24 01/09 @ 102   5,066,909  
              15,384,309  
        Kansas—1.0%      
AAA   6,440   Wyandotte Cnty. Unified Gov't. Spl. Oblig. RB, Intl. Speedway Proj.,      
              Zero Coupon, 12/01/20, MBIA No Opt. Call   3,227,342  
        Kentucky—1.3%      
BBB   3,750   Maysville Sld. Wst. Disp. RB, Inland Container Corp. Proj., 6.90%, 9/01/22 09/13 @ 102   4,108,800  
        Louisiana—0.7%      
BBB   2,000   De Soto Parish Env. Impvt. RB, Ser. A, 5.85%, 11/01/27 11/13 @ 100   2,056,480  
        Maryland—5.6%      
        Frederick Cnty. ST, Urbana Cmnty. Dev. Auth. Proj.,      
NR   3,000         6.625%, 7/01/25 07/07 @ 102   3,100,770  
NR   5,171         Ser. A, 5.80%, 7/01/20 07/07 @ 102   5,235,793  
BBB+   8,500   Hlth. & Higher Edl. Facs. RB, Auth. Medstar Hlth. Proj., 5.375%, 8/15/24 08/14 @ 100   8,880,460  
              17,217,023  
        Massachusetts—1.5%      
BBB   4,500   Dev. Fin. Agcy. Sld. Wst. Disp. RB, Wst. Mgmt., Inc. Proj., 5.45%, 6/01/14 No Opt. Call   4,769,955  
        Minnesota—0.4%      
A2   1,250   Higher Ed. Facs. Auth. RB, Univ. of St. Thomas Proj., Ser. 5, 5.00%, 10/01/24 10/14 @ 100   1,291,900  
        Mississippi—1.0%      
BBB   3,000   Warren Cnty. Env. Impvt. RB, Intl. Paper Proj., Ser. A, 5.85%, 11/01/27 11/13 @ 100   3,053,040  
        Missouri—3.5%      
BBB+   5,000   Dev. Fin. Brd. RB, Branson Landing Proj., Ser. A, 5.50%, 12/01/24 06/14 @ 100   5,213,000  
AA   5,500   Hlth. & Edu. Fac. RB, BJC Hlth. Sys. Proj., Ser. A, 5.00%, 5/15/20 05/15 @ 100   5,728,470  
              10,941,470  
        Multi-State—7.3%      
        Charter Mac Equity Issuer Trust,      
A3   1,000 4        Ser. A, 5.75%, 4/30/15 No Opt. Call   1,057,100  
A3   2,500 4        Ser. A, 6.00%, 4/30/19 No Opt. Call   2,702,700  
Baa1   4,000 4        Ser. B, 6.00%, 4/30/15 No Opt. Call   4,146,920  
Baa1   2,500 4        Ser. B, 6.30%, 4/30/19 No Opt. Call   2,639,150  
        Munimae TE Bond Subsidiary LLC,      
Baa2   5,000 4        Ser. C1, 5.40%, 6/30/49 09/14 @ 100   4,993,200  
Baa2   5,000 4        Ser. C2, 5.80%, 6/30/49 09/19 @ 100   4,949,300  
Baa3   2,000 4        Ser. D, 5.90%, 11/29/49 09/15 @ 101   1,999,980  
              22,488,350  
        New Hampshire—1.7%      
A-   5,000   Hlth. & Ed. Fac. RB, Elliot Hosp. Proj., Ser. B, 5.60%, 10/01/22 10/13 @ 100   5,271,600  
        New Jersey—11.6%      
        Econ. Dev. Auth. RB,      
BBB   11,500         Cigarette Tax Proj., 5.50%, 6/15/24 06/12 @ 100   11,999,330  
B   5,000         Continental Airlines, Inc. Proj., 7.00%, 11/15/30 11/10 @ 101   5,009,950  
B   1,500         Continental Airlines, Inc. Proj., 9.00%, 6/01/33 06/13 @ 101   1,636,485  
BBB-   1,000         First Mtg. Winchester Proj., Ser. A, 4.80%, 11/01/13 No Opt. Call   1,000,610  
Baa3   7,500         Kapkowski Rd. Landfill Proj., 6.50%, 4/01/31 No Opt. Call   8,598,750  
Baa1   4,000   Hlth. Care Fac. Fin. Auth. RB, Cap. Hlth. Sys. Oblig. Grp. Proj., Ser. A, 5.75%, 7/01/23 07/13 @ 100   4,264,960  
        Middlesex Cnty. Impvt. Auth. RB,      
NR   2,500         Heldrich Ctr. Hotel Proj., Ser. B, 6.125%, 1/01/25 01/15 @ 100   2,432,050  
Baa1   1,000         Str. Student Hsg. Proj., Ser. A, 5.00%, 8/15/23 08/14 @ 100   1,007,650  
              35,949,785  
        New York—8.2%      
        New York City Indl. Dev. Agcy. RB, American Airlines, JFK Intl. Arpt. Proj.,      
B-   5,635         7.625%, 8/01/25 08/16 @ 101   6,192,189  
B-   5,000         7.75%, 8/01/31 08/16 @ 101   5,509,150  
AAA   8,500   St. Energy Research & Dev. RB, Brlyn Union Gas/Keyspan Proj., Ser. A, 4.70%, 2/01/24, FGIC 02/16 @ 100   8,468,975  
AA-   5,000   Tobacco Settlement Fin. Corp. SA, Ser. B1, 5.50%, 6/01/20 No Opt. Call   5,394,650  
              25,564,964  

2

BlackRock Municipal 2020 Term Trust (BKK) (continued)

  Principal          
    Amount     Option Call    
Rating1   (000)   Description Provisions2   Value  
      Ohio—5.0%      
        Cuyahoga Cnty. RB, Cleveland Clinic Hlth. Sys. Proj.,      
Aa3   $ 3,000         6.00%, 1/01/19 07/13 @ 100   $ 3,345,720  
Aa3   10,000         6.00%, 1/01/20 07/13 @ 100   11,132,600  
NR   1,100   Pinnacle Cmnty. Infrastructure Fin. Auth. Facs. RB, Ser. A, 6.00%, 12/01/22 12/14 @ 101   1,135,431  
              15,613,751  
        Oklahoma—1.2%      
B-   3,350   Tulsa Mun. Arpt. Trust RB, Ser. A, 7.75%, 6/01/35 No Opt. Call   3,668,552  
        Pennsylvania—6.2%      
BBB+   6,680   Higher Edl. Fac. RB, La Salle Univ. Proj., 5.50%, 5/01/26 05/13 @ 100   7,010,459  
A+   10,000   Lancaster Cnty. Hosp. Auth. RB, Gen. Hosp. Proj., 5.75%, 3/15/20 09/13 @ 100   10,842,200  
NR   1,275   Montgomery Cnty. Indl. Dev. Auth. RB, Whitemarsh Continuing Care Proj., 6.00%, 2/01/21 02/15 @ 100   1,344,067  
              19,196,726  
        Puerto Rico—11.4%      
A3   10,900   Elec. Pwr. Auth. RB, Ser. NN, 5.125%, 7/01/24 07/13 @ 100   11,384,614  
        Pub. Impvt. GO,      
BBB   5,000         Ser. A, 5.25%, 7/01/22 07/13 @ 100   5,216,600  
BBB   11,000         Ser. A, 5.25%, 7/01/23 07/13 @ 100   11,455,840  
BBB   7,000         Ser. A, 5.25%, 7/01/24 07/13 @ 100   7,276,920  
              35,333,974  
        Rhode Island—1.5%      
BBB   4,500 3  Hlth. & Edl. Bldg. Corp. Hosp. Fin. RB, Ser. A, 5.875%, 9/15/08 N/A   4,587,300  
        Texas—5.8%      
BBB   1,100   Brazos River Auth. PCRB, TXU Energy Co. LLC Proj., Ser. A, 6.75%, 4/01/38 No Opt. Call   1,238,633  
BBB-   3,500   Port Corpus Christi Indl. Dev. Corp. RB, Valero Proj., Ser. C, 5.40%, 4/01/18 04/08 @ 102   3,640,350  
        Tpke. Auth. RB, Central Texas Tpke. Sys. Proj.,      
AAA   7,990         Ser. A, Zero Coupon, 8/15/21, AMBAC No Opt. Call   3,949,457  
AAA   8,450         Ser. A, Zero Coupon, 8/15/24, AMBAC No Opt. Call   3,600,883  
        Weatherford Indpt. Sch. Dist. GO,      
AAA   6,945         Zero Coupon, 2/15/23 02/11 @ 50.236   2,822,239  
AAA   6,945         Zero Coupon, 2/15/24 02/11 @ 47.435   2,661,116  
              17,912,678  
        Trust Territories—1.3%      
A   4,000 4  San Manuel Entertainment Auth., 2004 Gaming Proj., Ser.C, 4.50%, 12/01/16 12/13 @ 102   3,936,520  
        U.S. Virgin Islands—0.3%      
BBB   1,000   Pub. Fin. Auth. RB, Sen. Lien Matching Fund Loan, Ser. A, 5.25%, 10/01/17 10/14 @ 100   1,051,710  
        Virginia—7.6%      
NR   5,000   Celebrate North Cmnty. Dev. Auth. SA, Ser. B, 6.60%, 3/01/25 03/14 @ 102   5,239,200  
BBB   10,000   Charles City Cnty. Econ. Dev. Auth. Sld. Wst. Disp. RB, 5.125%, 8/01/27 03/06 @ 100   10,083,300  
Baa1   7,500   Mecklenburg Cnty. Ind. Dev. Auth. RB, Exempt FAC-UAE LP Proj., 6.50%, 10/15/17 10/12 @ 100   8,207,175  
              23,529,675  
        Washington—2.5%      
        Washington GO,      
AAA   10,000         Ser. S-5, Zero Coupon, 1/01/19, FGIC No Opt. Call   5,623,600  
AAA   4,630         Mtr. Veh. Proj., Ser. F, Zero Coupon, 12/01/21, MBIA No Opt. Call   2,261,385  
              7,884,985  
        Wisconsin—2.1%      
        Hlth. & Ed. Fac. Auth. RB, Wheaton Franciscan Svcs. Proj.,      
A   2,880         5.50%, 8/15/17 08/13 @ 100   3,054,903  
A   3,190         5.50%, 8/15/18 08/13 @ 100   3,371,447  
              6,426,350  
        Total Long-Term Investments (cost $456,322,584)     477,778,745  

3

BlackRock Municipal 2020 Term Trust (BKK) (continued)

  Principal      
    Amount      
Rating1   (000)   Description Value  
      SHORT-TERM INVESTMENTS—0.7%  
        New York—0.1%  
A-1+   $ 300 5  Triborough Brdg. & Tunl. Auth. RB, 3.15%, 4/06/06, FRWD $ 300,000  
        North Dakota—0.1%  
VMIG1   300 5  Grand Forks Hosp. Fac. RB, United Hosp. Oblig. Grp. Proj., 3.27%, 4/03/06, FRDD 300,000  
    Shares      
    (000)   
        MONEY MARKET FUND—0.5%  
NR   1,750   AIM Tax Free Investment Co. Cash Reserve Porfolio 1,750,000  
        Total Short-Term Investments (cost $2,350,000) 2,350,000  
        Total Investments—154.8% (cost $458,672,5846) $ 480,128,745  
        Other assets in excess of liabilities—2.5% 7,661,235  
        Preferred shares at redemption value, including dividends payable—(57.3)% (177,652,455)  
        Net Assets Applicable to Common Shareholders—100%
$ 310,137,525
 
1   Using the higher of Standard & Poor’s, Moody’s Investors Service or Fitch’s ratings.  
2   Date (month/year) and price of the earliest optional call or redemption. There may be other call provisions at varying prices at later dates.  
3   This bond is prerefunded. U.S. government securities, held in escrow, are used to pay interest on this security, as well as retire the bond in full at the date indicated, typically at a premium to par.  
4   Security is not registered under the Securities Act of 1933. These securities may be resold in transactions in accordance with Rule 144A under that Act, to qualified institutional buyers. As of March 31, 2006, the Trust held 9.2% of its net assets, with a current market value of $28,586,098, in securities restricted as to resale.  
5   For purposes of amortized cost valuation, the maturity date of this instrument is considered to be the earlier of the next date on which the security can be redeemed at par, or the next date on which the rate of interest is adjusted. Rate shown is rate as of March 31, 2006.  
6   Cost for Federal income tax purposes is $458,652,591. The net unrealized appreciation on a tax basis is $21,476,154, consisting of $21,814,648 gross unrealized appreciation and $338,494 gross unrealized depreciation.

 

KEY TO ABBREVIATIONS

ACA   —   American Capital Access   MBIA   —   Municipal Bond Insurance Assoc.   
AMBAC   —   American Municipal Bond Assurance Corp.   PCRB   —   Pollution Control Revenue Bond   
FGIC   —   Financial Guaranty Insurance Co.   RB   —   Revenue Bond   
FRDD   —   Floating Rate Daily Demand   SA   —   Special Assesment   
FRWD   —   Floating Rate Weekly Demand   ST   —   Special Tax   
FSA   —   Financial Security Assurance   TA   —   Tax Allocation   
GO   —   General Obligation          
 

4

Item 2. Controls and Procedures.

(a) The Registrant's principal executive and principal financial officers have evaluated the Registrant's disclosure controls and procedures within 90 days of this filing and have concluded, as of that date, that the Registrant’s disclosure controls and procedures were reasonably designed to ensure that information required to be disclosed by the Registrant in this Form N-Q was recorded, processed, summarized, and reported within the required time periods and that information to be disclosed by the Registrant in this Form N-Q was accumulated and communicated to the Registrant’s management, including its principal executive and principal financial officers, as appropriate, to allow timely decisions regarding required disclosure.

(b) 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.

Separate certifications of the Registrant’s Principal Executive and Financial Officers pursuant to Section 302 of the Sarbanes-Oxley Act of 2002 are attached as EX-99.CERT.

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)___BlackRock Municipal 2020 Term Trust___

By:___/s/ Henry Gabbay____________________________________
Name: Henry Gabbay
Title: Treasurer and Principal Financial Officer
Date: May 25, 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:___/s/ Robert S. Kapito___________________________________
Name: Robert S. Kapito
Title: President and Principal Executive Officer
Date: May 25, 2006

By:__/s/ Henry Gabbay______________________________________
Name: Henry Gabbay
Title: Treasurer and Principal Financial Officer
Date: May 25, 2006