The House committee investigating the Korean influence-buying scandal finally got to question its star witness, Tongsun Park, yesterday, and several committee members offered the same description of the secret session: "boring."

Members of the Committee on Standards of Official Conduct said their special counsel, Leon Jaworski, devoted the five-hour hearing to a methodical and sometimes tedious review of Park's background in South Korea and the businesses he opearted in the United States after coming here in the early 1960s.

With nine more days of Park's testimony yet to go, the committee members said, Jaworski seemed in no hurry to get to specific questions about allegations that Park offered bribes and favors to U.S. officials to win their support for the South Korean government.

"It was boring," said Rep. Millicent H. Fenwick (R-N.J.). "A lot of it went awfully slowly."

"Don't even bother to ask," quipped Rep. Richardson Preyer (D-N.C.) to a reporter who approached him after the closed hearing. "There's nothing worth leaking yet."

Committee Chairman John J. Flynt Jr. (D-Ga.) said he didn't agree with colleagues who found the session boring, because "Mr. Park is a very interesting man." But Flynt added that the questionin g produced no information that has not already been revealed in newspapers or by federal investigators pursuing the Korean case.

Since it began its investigation a year ago, the committeee has been trying to cajole or threaten Park into answering its questions. Park returned from Seoul to appear before the committee only after extended negotiations in which he won immunity from prosecution on bribery and conspiracy charges in return for truthful testimony.

Thus there was considerable hoopla in the Rayburn House Office Building yesterday when Park arrived at 9.35 a.m. for his first session before the committee.

Before entering the committee room, the Korean stepped onto a platform before a crowded phalanx of reporters and television cameras to promise his cooperation with the investigators.

"I'm going to get in there and let them ask any question . . . and I'll do my best to clear the air so the Congress of this country can get back to its normal life," he said with a grin.

Park, whose Jaunty charm won him friendships with several members of Congress, looked fatigued yesterday. He told reporters he was "plainly tired" from the continued questioning about the Korean influence-Buying effort.

In Seoul last month, Park was interrogated by Justice Department probers seeking evidence of criminal misconduct in the Korean affair. After his 10 days before the House committee, he is scheduled to face questions in a separate Senate investigation of the Korean case, and then to testify in the criminal trial of former Rep. Richard Hanna (D-Calif.), who has been charged with bribery and conspiracy in the case.

Rep. Bruce Caputo (R.N.Y.), a committee member who sat in on Park's interrogation last month, said that Jaworski's questioning yesterday was tougher and "more adversary" than that of the Justice Department officials who questioned Park in Seoul.

"In most cases where Park was evasive," Caputo said, "Jaworski or one of his staff aides would direct him to get back on point.

"Where he was incomplete, Mr. Jaworski would bring up some documentary evidence to challenge his answer. "That didn't happen as much in the Justice Department's interrogation."

Caputo said the relatively tedious questioning yesterday was necessary to lay a basis for specific questions. He said the committee "may get down to brass tacks on specific cases" today.

Jaworski would say only that the first day's questioning "went according to plan."

Park was put under oath at the start of the session, but no lie detector was used during the questioning. Committee members expressed varying degrees of trust in what he said.