ALfred Barrett is president of the Glassmanor Citizens Association, a group only about a year old that hopes to turn that area of southern Prince George's County back into neighborhood - a community where people feel good about themselves and where they live.

The group is pursuing its goals against a backdrop of more than a decade of population shifts and social changes and community problems that include high crime and a declining business district.

The citizens association, with only 77 members so far, is trying to right some of the things they feel have gone wrong with the neighborhood. To do so, they are monitoring county plans for the Oxon Hill area suburb, lobbying for increased county services, encouraging upkeep of homes and streets in the area and providing recreation for neighborhood children, its members said.

Glassmanor is a jumble of neat red brick and frame houses and townhouses crowded by duplexes and high-rise apartment buildings, east of the Eastover Shopping Center. Just across the District line, its boundaries are, roughly, Southern Avenue, Owens Road, Indian Head Highway and the undeveloped area just south of the Glassmanor Elementary School.

The changes that have taken place over the years include a transition from an almost white neighborhood to predominantly black, according to residents. From 1960, when black population in the census tract which includes Glassmanor amounted to less than one per cent, it grew to 25.7 per cent in 1970. Since then, according to residents, the neighborhood has become majority black.

It was a turnover that drove many former residents of the neighborhood away in panic, dissolving former community ties and leaving a newly repopulated suburb behind, according to some former and current homeowners.

Other changes have taken place too. Statistics on median earnings and median value of housing indicated that earnings and housing values in the area that includes Glassmanor have not risen as rapidly as they have in the county as a whole.

Out of some of the changes grew bitterness. Some black fam ilies who moved to Glassmanor felt that their white neighbors shunned them and that county services declined as the area became more black. (County officials deny this.) Some whites felt pushed out and that their neighborhood had been damaged by the black influx.

Whatever the causes of the problems, the neighbors who have founded the Glassmanor group think they can do something about them.

Barrett moved to Glassmanor from Northeast Washington about two years ago. His wife saw the house and fell in love with it, he said.

He said he found that "it was not a progressive area, not as progressive as I thought. There was nothing going on here. No community outlets," he said. "We don't have a church and there is no community school because the children are bussed out of the community." Glassmanor children may end up in any one of seven elementary schools since students have been moved around the achieve racial balance, according to county school officials.

It was this lack of focus for the community that prompted some Glassmanor residents to form the civic association in June, 1975.

"It's been a forgotten area of the county," said Barrett. "The people themselves are not concerned about building the community back up, but that's beginning to change."

Marvin L. Gay, who moved to Glassmanor in 1969, said he had seen the neighborhood change from the community he moved into to a less cohesive neighborhood. In his first years there, as the neighborhood was making a transition from almost entirely white to more integrated, he said that telephone calls from real estate people suggesting that he sell his house were a frequent phenomena. (Some white residents and former residents said they found the same pressure to sell.)

"They didn't say a lot of blacks are moving in now," Gay said of the real estates sales people's calls, but on the other hand, the calls came only a the turnover in racial makeup occured, said Gay.

"I didn't want to pay $350 a month to live in an area that was getting rejected," he said. The message he took from the call was, "You just made a $30,000 mistake," he said. "I thought I had just moved into a nice neighborhood. To find it was now not considered so nice because I moved there didn't sell well.

"For a while, he said, new residents seemed preoccupied with meeting their financial obligations, rather than with community activities. Now, he said, some black families who hve lived in Glassmanor are moving on, dissatisfied.

"If people would just get more involved where they are and take more responsibility for what they find, they wouldn't have to keep moving," he said.

Gay is living temporarily in Marlow Heights after the end of his marriage and the sale of his houses, but he remains active in the civic association.

The group's activities have included lobbying for a recreation center for the neighborhood and creation of two neighborhood football teams to play in the Beltway League.

The recreation center is expected to be under construction beginning this spring. The football teams, with about 45 members, just ended the season with a banquet featuring as speakers a University of Maryland football player and television personality Petey Greene.

Also, said Barrett and Gay, they are trying to form an alliance with area businesses to improve relations. The business area, which includes a strip along the Indian Head Highway and Eastover Shopping Center, has lost several major businesses in the past years. A Giant food store moved out in 1972 because of seriously declining revenues, according to a spokesman for Giant. Woodward & Lothrop closed a small store in the Eastover center the same year. The Glassmanor Drug Fair closed about a year ago.

Crime has been another problem in the area. The crime rate is high in Glassmanor, particularly for rape and assault with intent to rape, burglaries and street robberies, according to county police.

Barrett said the group hopes to work with police on crime prevention. The group's most ambitious plan, however, is a monpartisan voter registration campaign in the spring.

"We understand the politics of the situation," said Gray. "The county will put its services where (officials) have support."