Name of Issuer: 
	Mercury Interactive

Type or Class of Security: 
	Common

CUSIP Number: 
	589405109

1.  Name of Reporting Person
    S.S. or I.R.S. Identification No. of Above Person
		
	Friess Associates, Inc.	51-0253305

2.  Check the Appropriate Box if a Member of a Group

	(a)
	(b)

3.  SEC Use Only


4.  Citizenship or Place of Organization

	115 E. Snow King
	Jackson, WY 83001

5.  Sole Voting Power

	855,000

6.  Shared Voting Power

	n/a

7.  Sole Dispositive Power

	855,000

8.  Shared Dispositive Power

	n/a

9.  Aggregate Amount Benefically Owned by Each Reporting Person

	855,000

10. Check Box if the Aggregate Amount in Row (9) Excludes Certain Shares

	n/a

11. Percent of Class Represented by amount in #9

	5.2

12. Type of Reporting Person

	I.A.

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 purposes or effect.

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.

January 29, 1998


Foster S. Friess
President