Yuri Alekseyevitch Asseyev, the Soviet exchange student promised political asylum in the United States last month, apparently made a second attempt on his life in Cambridge Saturday.

Asseyev, formerly a professor of philosophy at the University of Leningrad attempted to jump onto the track in the Harvard Square MTA station at 4:30 p.m. Saturday. A man in his company told an MTA starter that Asseyev was about to jump, and a fare collector, Daniel J. Magoon, ran from his booth and stopped Asseyev three to five feet from the edge of the platform, an MTA official said last night.

After a struggle with Magoon, Asseyev was taken by police to Cambridge Hospital; he was later transferred to McLean Hospital, an institution for psychiatric care in Belmont. The MTA labelled as totally false yesterday's reports that Asseyev had been lying on the track when he was saved.

A participant in the Soviet-American cultural exchange program, 35-year-old Asseyev had been studying in the Soc Rel Department at Harvard since September. He was concentrating on logical positivism and the Western sociology of knowledge under a flexible academic arrangement.

On Jan. 2 Asseyev jumped from a window of the apartment of Mr. and Mrs. Gerald Platt at 369 Harvard St. He was hospitalized until Jan. 15, and after his release was reportedly still under psychiatric care at the University Health Services.

The State Department, after a Jan. 4 meeting with Asseyev in the presence of Soviet officials, granted him permission to stay in the United States after his official visa expires in June. He has a wife and child in the Soviet Union, and according to friends has been under great emotional stress.

Status Now In Doubt

Robert J. McCloskey, State Department press officer, said last night that Asseyev's status would now be "up in the air," since it is impossible to know his intentions at this point.

There has been no reaction whatsoever from the Soviet Union in regard to this incident, McCloskey said. He pointed out that since there would be no official change in Asseyev's status here until his visa expires in June, the Soviet professor is "free to reconsider" his decision to remain here permanently.

The United States would probably admit Asseyev's family upon his request, McCloskey said. There is some question, however, about the willingness of the Soviet Union to permit them to leave.

Police reports on the incident were labelled confidential and detailed information was closely guarded over the weekend, causing many sources to speculate that the case would have serious international repercussions. McCloskey dismissed the theory, however, and said that it was extremely unlikely that the Soviet Union had had any hand in Saturday's events.