A Milwaukee school administrator named last month as an assistant superintendent for the Anne Arundel County public schools system has decided not to take the $89,500 job.

Superintendent Carol S. Parham yesterday confirmed that Aquine Jackson recently changed his mind about taking the job, citing "family reasons."

"He thought the job was ideal, but his family came first. They have a very young child and were reluctant to move halfway across the country," she said. "We're just going to readvertise the position."

Dr. Parham said the Board of Education has had no trouble attracting job applicants, despite a year of negative publicity from a teacher-student sex scandal.

Dr. Jackson will continue as director of student services for the Milwaukee public school system. His title here would have been assistant superintendent for student support services.

Walter N. Chitwood, the county's chief administrative officer, was named assistant superintendent for administration at the same time that Mr. Jackson's appointment was announced.

Mr. Chitwood has worked in county government for 19 years, as director of recreation and parks, and director of public works. His salary will range from $59,721 to $89,582.