David K. Davoudlarian, the Annandale gynecologist accused in a civil suit of killing his wife, took the stand in his own defense yesterday and described his marriage as "very happy."

"I felt very relaxed. We never had any problems, just the normal marital discord," Davoudlarian testified. "We never had anything big, bad."

A seemingly confident, occasionally wisecracking Davoudlarian was on the stand for 90 minutes, testifying in a clear, strong voice to the jury as a crowd that overflowed the Fairfax County Circuit courtroom looked on.

Asked if his wife, Susan S. Davoudlarian, 40, had ever asked him for a divorce, Davoudlarian replied: "Never. Susan never suggested anything like that." Other witnesses have testified that Susan Davoudlarian told them she had asked him for a divorce because she was unhappy in the marriage.

Davoudlarian took the stand on the first day of the presentation of his defense and his testimony is expected to continue most of today. His testimony did not touch on the circumstances surrounding his wife's death.

Susan Davoudlarian was found strangled on June 12, 1983, her nude body wedged beneath the folded-down back seat of her station wagon, which was parked at Dulles International Airport.

No one has been charged in her death, and Davoudlarian previously has denied in sworn depositions that he had any involvement in it.

The suit being tried was brought by his wife's estate and seeks $10 million in damages from him.

The estate's case, laid out in two weeks of testimony from 45 witnesses, is nearly all circumstantial, focusing on the state of the Davoudlarian marriage, the doctor's temper and his behavior around the time his wife was killed.

Plato C. Cacheris, a defense attorney who questioned Davoudlarian yesterday, asked about $374,000 in insurance the doctor took out on his wife's life in the last four months she was alive.

"Was there any ulterior motive for taking out those policies, doctor?" Cacheris asked.

"No, they were for our protection," Davoudlarian replied.

At another point, Davoudlarian was asked about a party at which other witnesses have testified he angrily accused his wife of having an affair with a neighbor.

He said he "had no recollection" of making the accusation. He described the neighbor he is said to have accused as "a poker buddy."

Turning to the jury, he smiled and said: "He gives me advice on my lawn. His lawn is much better than mine." Later he told the jury, "I'm a lousy gardener."

Davoudlarian, 49, who occasionally mopped his brow in a stifling courtroom where all seats were taken and two dozen people stood, appeared to be in a jovial mood.

Dressed in light blue pants, a starched, white shirt, a blue blazer and blue tie, he began the day at the main entrance to the courthouse. He shed his jacket and stood for 30 minutes welcoming the witnesses who would testify on his behalf, good-naturedly directing them to the proper courtroom.

Stepping down from the witness stand just before 5 p.m., he smiled and joked with his attorneys and the attorneys who are pressing the suit against him, as jurors and spectators filed out of the courtroom.

Much of his testimony concerned his boyhood in Syria and Lebanon, his medical education in Beirut and the United States, and his courtship and early years of his marriage to Susan. It was the second marriage for both.

He said he and his wife "did disagree" about how Susan's two daughters from her previous marriage should be raised.

"Being of a European background, I felt a little more strongly that there should be rules and regulations," he said. "Susan was more of a butterfly-type person, inclined to let things go."

Those daughters have filed a separate civil suit against their stepfather, also alleging that he killed their mother and seeking to block him from collecting $750,000 in life insurance and property