A Fairfax County jury, in what legal experts say is the first verdict of its kind, has awarded $25,000, to a divorced father who claims he suffered severe emotional problems because his former wife prevented him from visiting their children.

The verdict was won by Harold H. Memmer, a civilian Army worker at Fort Belvoir, who had become so depressed, his sister testified, that she feared "he would do away with himself."

An official of the American Bar Association's family law section yesterday described the award as "precedent-setting" and predicted it would serve as "a warning" to divorced parents who attempt to evade court orders granting visitation rights to their former spouses.

"I think this is very significant," agreed Paul M. Robinson, acting president of the Northern Virginia-Washington chapter of Fathers United for Equal Rights, a group of divorced fathers. "It's always been difficult to get courts to enforce visitation rights."

But it was a bittersweet victory for Memmer, 48, who lives alone in a split-level house in the Woodlawn Terrace area of Fairfax County just north of the Army post. The three children involved in the case shunned him as they left the courtroom of Fairfax Circuit Judge Thomas J. Middleton. a"When I left the courtroom, my daughters wouldn't talk with me," Memmer said yesterday.

In his lawsuit against his former wife, Memmer charged that she repeatedly thwarted his efforts to visit their three daughters despite court orders allowing him visitation rights. Memmer alleged that his wife, who has remarried twice since their 1976 divorce and now lives in Evansville, Ind., had encouraged his daughters not to talk to him, hung up when he called on the telephone and "vilified" him in the children's presence.

"His children were his life," said Memmer's lawyer, B. VanDenburg Hall, "and his life was gone."

Memmer himself said as much in an interview yesterday as he recalled happier days with his three daughters, aged 13 to 20. "Let's face it," he said. "If you take the best thing you know and it's removed, what's the effect? Those kids meant more to me than anything."

Once when he tried to visit the children in Evansville, Memmer testified, his former wife "slammed the door in my face and in fact almost caught my hand in the door."

Memmer's attorney, Hall, said the jury of four women and three men apparently agreed with his belief that the former Mrs. Memmer "brainwashed the children about their father."

Lawyers for the woman asked Middleton to set the jury's verdict aside and he rejected their request, but agreed to consider written arguments on their reasoning. Neither the former Mrs. Memmer nor her lawyers could be reached for comment yesterday.

At the one-day trial 20-year-old Donna Jean, Memmer's oldest daughter and now married, testified that on the one occasion when she and her sisters traveled to Fairfax to be with their father for a short stay his "house was filthy. There were ants crawling all over the floor. The dishes were dusty. It was just insects all over the place and the smell was so unbearable it was ridiculous."

Hall, in his closing argument before the jury, responded: "I ask you, is it logical that a man like this, who has tried so much to see his children, would drive out there [to Evansville] and drive 14 hours back with them to a home full of bugs and dirt? Is that credible?"

The jury apparently decided it wasn't. After deliberating for slightly more than an hour, they decided Wednesday that the former Mrs. Memmer, whose present married name is Day, had, as Hall charged, "intentionally inflicted severe emotional stress upon the children's father."

Hall said liability for emotional, as opposed to physical, stress or suffering, was established in Virginia by a 1974 State Supreme Court case, in which the court held that a defendant could be liable for emotional stress if it was "intentional or reckless," intolerable" and "severe."

Besides hearing Memmer's sister, Aileen Comiez, testify about what she feared were her brother's suicidal tendeicies, the jury was also told by Memmer's physician, Dr. Richard J. Redding, that the plaintiff suffered depression "in the form of loss of sleep, fatigue, sadness and loss of joy due . . . to loss of the children."

Though Memmer said he saw his daugthers turn away from him after they went to live with their mother in 1975, he said yesterday there were many happier moments in earlier years.

"We'd go canoeing, fishing," he said. "After church, we'd do things like go to the Washington Monument, climb up and down the stairs to the top. I remember Karen [at 13 the youngest daughter] was too small and we'd carry her . . . All that was taken away from me.'

When he tried to see his children after the split-up and failed, Memmer said, "I felt terrible, I was bitter, I was consumed by an obsession: What could I do to get them back? I couldn't snatch the kids. I couldn't put that on them. I had faith in the system . . . You've got to have faith, man."