UNITED STATES

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SECURITIES AND EXCHANGE COMMISSION

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FORM 12b-25

SEC FILE NUMBER
0-24786

CUSIP NUMBER

NOTIFICATION OF LATE FILING

045327 10 3

(Check one):

o Form 10-K

o Form 20-F

o Form 11-K

x Form 10-Q

o Form 10-D

o Form N-SAR

o Form N-CSR

For Period Ended:

December 31, 2007

o Transition Report on Form 10-K

o Transition Report on Form 20-F

o Transition Report on Form 11-K

o Transition Report on Form 10-Q

o Transition Report on Form N-SAR

For the Transition Period Ended:

Read Instructions (on back page) Before Preparing Form. Please Print or Type.
Nothing in this form shall be construed to imply that the Commission has verified any information contained herein.

If the notification relates to a portion of the filing checked above, identify the Item(s) to which the notification relates:

PART I — REGISTRANT INFORMATION

ASPEN TECHNOLOGY, INC.

Full Name of Registrant

Former Name if Applicable

200 Wheeler Road

Address of Principal Executive Office (Street and Number)

Burlington, MA 01803

City, State and Zip Code

 (a)

The reason described in reasonable detail in Part III of this form could not be eliminated without unreasonable effort or expense

o

 (b)

The subject annual report, semi-annual report, transition report on Form 10-K, Form 20-F, Form 11-K, Form N-SAR or Form N-CSR, or portion thereof, will be filed on or before the fifteenth calendar day following the prescribed due date; or the subject quarterly report or transition report on Form 10-Q or subject distribution report on Form 10-D, or portion thereof, will be filed on or before the fifth calendar day following the prescribed due date; and

 (c)

The accountant’s statement or other exhibit required by Rule 12b-25(c) has been attached if applicable.

SEC 1344 (03-05)

Persons who are to respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB control number.

(1)

Name and telephone number of person to contact in regard to this notification

Bradley T. Miller

(781)

221-6400

(Name)

(Area Code)

(Telephone Number)

(2)

Have all other periodic reports required under Section 13 or 15(d) of the Securities Exchange Act of 1934 or Section 30 of the Investment Company Act of 1940 during the preceding 12 months or for such shorter period that the registrant was required to file such report(s) been filed ? If answer is no, identify report(s).

o Yes    x No

We have not yet filed our Form 10-K for the period ended June 30, 2007 and our Form 10-Q for the period ended September 30, 2007.

(3)

Is it anticipated that any significant change in results of operations from the corresponding period for the last fiscal year will be reflected by the earnings statements to be included in the subject report or portion thereof?

x Yes    o No

If so, attach an explanation of the anticipated change, both narratively and quantitatively, and, if appropriate, state the reasons why a reasonable estimate of the results cannot be made.

Due to the matters described in Part III above, we cannot provide at this time an estimate of our results of operations for the fiscal quarter ended December 31, 2007.  We previously announced on January 16, 2008 that we anticipate reporting cash and cash equivalents of $131 million at December 31, 2007, which is an increase from $128 million at September 30, 2007.  The anticipated balance of cash and cash equivalents should be considered a preliminary estimate pending completion of the audit and the finalization of our financial statements for the fiscal year ended June 30, 2007. 

We also announced on February 11, 2008 that, in connection with the detailed review of other accounts in our financial statements referenced above, and additional work in preparing our Form 10-K for fiscal 2007, we currently expect to record charges for additional tax liabilities totaling approximately $20 million for the periods fiscal 2002 through fiscal 2007.  The estimated charges primarily relate to income taxes arising from transactions between entities within the consolidated subsidiaries of the company.  These are preliminary estimates and are subject to change. 

ASPEN TECHNOLOGY, INC.

Date

February 12, 2008

By

/s/ Bradley T. Miller

Bradley T. Miller

Senior Vice President and Chief Financial
Officer