Backus, whose 847-167-3 record and nine national titles in 21 years make her the winningest college softball coach, will be reassigned within the athletic department at her request, the school announced and will not coach during the 1997 season.
Sue Enquist, co-head coach for the past eight years, will become the lone head coach.
"My primary reason for stepping down has to do with the illness and death of my mother in early October," Backus said in a statement.
"That, plus the ongoing NCAA probe of the softball program have created a level of stress that I feel is best to put behind me at this time. I've had a great career at UCLA, but it's time for a change."
The NCAA is reviewing UCLA's responses to the issues of its inquiry, and it is anticipated that UCLA representatives will appear at the Committee of Infractions hearing, scheduled Jan. 31-Feb. 2 in Phoenix.
The inquiry was prompted by a Times' investigation into star pitcher Tanya Harding, who led the Bruins to the 1995 NCAA title.
UCLA was put on probation by the Pacific 10 Conference after awarding 2 1/2 more scholarships than allowed for the 1993-94 and '94-95 school years.
One of the scholarships went to Harding, a member of the Australian national team that later beat the United States in the 1996 Olympics.