Form: SC 13G

Schedule filed to report acquisition of beneficial ownership of 5% or more of a class of equity securities by passive investors and certain institutions

February 8, 2001

SC 13G: Schedule filed to report acquisition of beneficial ownership of 5% or more of a class of equity securities by passive investors and certain institutions

Published on February 8, 2001








SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G


(Rule 13d-102)


INFORMATION STATEMENT PURSUANT TO RULES 13d-1 AND 13d-2


Under the Securities Exchange Act of 1934
(Amendment No. )


AVALON BAY COMMUNITIES INC
-----------------------------------------------------
(Name of Issuer)
Common Stock
-----------------------------------------------------
(Title of Class of Securities)

053484101
-----------------------------------------------------
(CUSIP Number)



Check the following box if a fee is being paid with this statement [x].


- ----------
*The remainder of this cover page shall be filled out for a reporting person's
initial filing on this form with respect to the subject class of securities, and
for any subsequent amendment containing information which would alter the
disclosures provided in a prior cover page.

The information required in the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the Securities Exchange Act of
1934 ("Act") or otherwise subject to the liabilities of that section of the Act
but shall be subject to all other provisions of the Act (however, see the
Notes).


CUSIP No. 053484101 13G Page 2 of 8 Pages



- --------------------------------------------------------------------------------
1. NAME OF REPORTING PERSON(S)
S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON(S)

Morgan Stanley Dean Witter & Co.
IRS # 39-314-5972



- --------------------------------------------------------------------------------
2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
(a) [ ]
(b) [ ]


- --------------------------------------------------------------------------------
3. SEC USE ONLY




- --------------------------------------------------------------------------------
4. CITIZENSHIP OR PLACE OF ORGANIZATION

The state of organization is Delaware.


- --------------------------------------------------------------------------------
NUMBER OF 5. SOLE VOTING POWER
SHARES 0
BENEFICIALLY --------------------------------------------------------------
OWNED BY 6. SHARED VOTING POWER
EACH 2,964,960
REPORTING --------------------------------------------------------------
PERSON 7. SOLE DISPOSITIVE POWER
WITH 0
--------------------------------------------------------------
8. SHARED DISPOSITIVE POWER
3,541,466
- --------------------------------------------------------------------------------
9. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

3,541,466
- --------------------------------------------------------------------------------
10. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*



- --------------------------------------------------------------------------------
11. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

5.28%

- --------------------------------------------------------------------------------
12. TYPE OF REPORTING PERSON*

IA, CO

- --------------------------------------------------------------------------------
*SEE INSTRUCTIONS BEFORE FILLING OUT!

CUSIP No. 053484101 13G Page 3 of 8 Pages



- --------------------------------------------------------------------------------
1. NAME OF REPORTING PERSON(S)
S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON(S)

Morgan Stanley Dean Witter Investment Management Inc.
IRS # 13-3040307


- --------------------------------------------------------------------------------
2. CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
(a) [ ]
(b) [ ]


- --------------------------------------------------------------------------------
3. SEC USE ONLY




- --------------------------------------------------------------------------------
4. CITIZENSHIP OR PLACE OF ORGANIZATION

The state of organization is Delaware.


- --------------------------------------------------------------------------------
NUMBER OF 5. SOLE VOTING POWER
SHARES 0
BENEFICIALLY --------------------------------------------------------------
OWNED BY 6. SHARED VOTING POWER
EACH 2,797,520
REPORTING --------------------------------------------------------------
PERSON 7. SOLE DISPOSITIVE POWER
WITH 0
--------------------------------------------------------------
8. SHARED DISPOSITIVE POWER
3,360,926
- --------------------------------------------------------------------------------
9. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

3,360,926
- --------------------------------------------------------------------------------
10. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*



- --------------------------------------------------------------------------------
11. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)
5.01%

- --------------------------------------------------------------------------------
12. TYPE OF REPORTING PERSON*

IA, CO


- --------------------------------------------------------------------------------
*SEE INSTRUCTIONS BEFORE FILLING OUT!


CUSIP No. 053484101 13G Page 4 of 8 Pages





Item 1. (a) Name of Issuer:
AVALON BAY COMMUNITIES INC
--------------------------------------------------------------
(b) Address of Issuer's Principal Executive Offices:
2900 EISENHOWER AVENUE
SUITE 300
ALEXANDRIA
VA
22314
--------------------------------------------------------------
Item 2. (a) Name of Person Filing:
(a) Morgan Stanley Dean Witter & Co.
(b) Morgan Stanley Dean Witter Investment Management Inc.
--------------------------------------------------------------
(b) Address of Principal Business Office, or if None, Residence:
(a) 1585 Broadway
New York, New York 10036

(b) 1221 Avenue of the Americas
New York, New York 10020
--------------------------------------------------------------
(c) Citizenship:
Incorporated by reference to Item 4 of the
cover page pertaining to each reporting person.

-------------------------------------------------
(d) Title of Class of Securities:
Common Stock
--------------------------------------------------------------
(e) CUSIP Number:
053484101
-------------------------------------------------

Item 3. (a) Morgan Stanley Dean Witter & Co. is (e) an Investment Adviser
registered under Section 203 of the Investment Advisers Act
of 1940.

(b) Morgan Stanley Dean Witter Investment Management Inc. is (e)
an Investment Adviser registered under Section 203 of the
Investment Advisers Act of 1940.


CUSIP No. 053484101 13-G Page 5 of 8 Pages



Item 4. Ownership.


Incorporated by reference to Items (5) - (9) and (11) of the
cover page.



Item 5. Ownership of Five Percent or Less of a Class.

Inapplicable

Item 6. Ownership of More Than Five Percent on Behalf of Another Person.

Accounts managed on a discretionary basis by Morgan Stanley Dean
Witter Investment Management Inc., a wholly owned subsidiary of
Morgan Stanley Dean Witter & Co., are known to have the right to
receive or the power to direct the receipt of dividends from, or
the proceeds from, the sale of such securities. No such account
holds more than 5 percent of the class.



Item 7. Identification and Classification of the Subsidiary which Acquired
the Security Being Reported on By the Parent Holding Company.


Item 8. Identification and Classification of Members of the Group.


Item 9. Notice of Dissolution of Group.


Item 10. Certification.

By signing below I certify that, to the best of my knowledge and
belief, the securities referred to above were acquired in the
ordinary course of business and were not acquired for the purpose
of and do not have the effect of changing or influencing the
control of the issuer of such securities and were not acquired in
connection with or as a participant in any transaction having
such purpose or effect.

CUSIP No. 053484101 13-G Page 6 of 8 Pages


Signature.


After reasonable inquiry and to the best of my knowledge and
belief, I certify that the information set forth in this
statement is true, complete and correct.


Date: February 08, 2001


Signature: /s/ Dennine Bullard
-----------------------------------------------------------------

Name/Title Dennine Bullard / Morgan Stanley & Co. Incorporated
-----------------------------------------------------------------
MORGAN STANLEY DEAN WITTER & CO.

Date: February 08, 2001


Signature: /s/ Donald P. Ryan
-----------------------------------------------------------------

Name/Title Donald P. Ryan / Principal Morgan Stanley Dean Witter Investment
Management Inc.
-----------------------------------------------------------------
MORGAN STANLEY DEAN WITTER INVESTMENT MANAGEMENT INC.



INDEX TO EXHIBITS PAGE
----------------- ----

EXHIBIT 1 Agreement to Make a Joint Filing 7

EXHIBIT 2 Secretary's Certificate Authorizing Dennine Bullard 8
to Sign on behalf of Morgan Stanley Dean Witter & Co.


* Attention. Intentional misstatements or omissions of fact constitute federal
criminal violations (see 18 U.S.C. 1001).

(022597DTI)