Fairfax County Supervisor Alan H. Magazine announced yesterday that he will not seek reelection because, after seven years on the board, he is tired of having too little time for himself or his family.

Magazine, a liberal Democrat who represents the highly urban Mason District of Fairfax, said in an interview he feels "a little ridiculous retiring at the age of 34," but that he is no longer willing to allow his $15,000-a-year job as a supervisor to dominate his life.

"For example, my wife and I have found that we are really looking for wardd to a weekend trip next month to Philadelphia I don't have anything against Philadelphians, but that is a pretty sad commentary on your life when you are desperately looking forward to spending time in Philadelphia," Magazine said.

The tall, youthful-looking supervisor, who at 27 was the youngest person even elected to the board, yesterady compared himself to 33-year-old Metro manager Theodore C. Lutz, who announced last week that he was retiring because he was "burned out" by the demands of his job.

Magazine, an outspoken supervisor who in the past has criticized his conservative colleagues on the board for "racist" and "unsophisticated" behavior, holds a full-time job as a $42,000-a-year consultant to the U.S. Environmental Protection Agency. He said the EPA job and his duties as a supervisor representing nearly 70,000 constitutents leave him little time for his family.

"I don't want to have to look backsome day and say I didn't spend enought time with my children," Magazine said. He and his wife, June Ann, have a 2-year-old daughter and are expecting another child this spring.

Magazine, who has a doctorate in public administration and urban affairs, moved to Fairfax County in 1970 because, he said, it was easier to get involved in politics in Fairfax than Montgomery County. A year later, he was elected supervisor by a margin of 14 votes.

"He came on full of steam, impatient to find solutions," supervisor Martha V. Pennino (D-Centreville) said yesterday. She said that over seven years, however, Magazine "slowed up to the pace of the rest of us."

As a supervisor, Magazine became known as a consumer advocate who pushed for the establishment of a county consumer protection commission, a tenant-landlord ordinance and a county-wide ban on nonreturnable bottles.

Since his reelection in 1975, Magazine said he has devoted less time to his job as supervisor, partially because he was soured by a political system that "is even more imperfect than I thought it was an a student."

"We have had to go hat in hand to Richmond every year. Our General Assembly is in the dark ages as far as allowing urban counties to deal with their own problems, such as land use and highway management," Magazine said.

He said other, more personal aspects of his office have made him unwilling to stay in politics.

"I take one hell of a lot of abuse. There have been revolting rumors about things in my personal life. There are nuts everywhere. If someone wants to get back at you, one of those nuts will start a rumor just to attack you. And don't think that some of those don't hurt," Magazine said.

The supervisor, who said he has put on 15 pounds because his work leaves him no time to play tennis, said he finds the long Monday meetings of the board, which often last 12 hours or longer, tedious. "In the afternoons, during those rezoning hearings, I've found myself bored to tears."

County polities, according to Magazine, is "stacked against young people" because of the difficulty of holding a full-time job while working 30 to 40 hours a week as a supervisor. "You are out of your mind if you run for supervisor for the money. It is impossible at the beginning of your profession to progress with divided attention," Magazine said.

Alluding to Magazine's complaint, Pennino said during yesterday's board meeting that she could give her job "the time because I'm a retired mother, but you (Magazine) are not a retired father."

Board elections for all nine seats will be held this fall, and several candidates, including Republican lawyer Tom M. Davis and Democrat Betsy Hinkle, owner of The Springfield Independent, have expressed interest in Magazine's job.