Yuri Andropov, elevated today to the Secretariat of the Soviet Central Committee, has been described by some Western analysts as a well-educated and enlightened man--even a closet liberal--despite the stigma attached to his post as head of the KGB security police.

While largely unknown in the West, East Europeans who have met Andropov have described him as an affable and efficient man who has managed to place considerable restraints on the KGB.

Apart from some 1970s statements supporting detente, however, there has not been much solid evidence that Andropov was anything other than a cautious and clever loyalist of President Leonid Brezhnev.

Andropov, 67, a tall man who wears glasses, is one of the most experienced members of the Politburo in foreign affairs.

He first gained attention as the Soviet ambassador to Hungary during the 1956 uprising there, when he was a key man in directing the Soviet moves that crushed the rebellion. More recently, he belonged to a "quick reaction group" of four or five Politburo members who were believed to be running the Soviet intervention in Afghanistan.

Andropov has always been regarded as a possible successor to Brezhnev, but his leadership of the KGB has been seen as a handicap by Western Kremlin-watchers.

Ever since Stalin's Great Terror, the secret police chief has automatically been ruled out as party chief. East German leader Erich Honecker once headed his country's secret police, however, and the Soviet party might applaud a similar choice during a time of internal strain.

Andropov is expected to relinquish formally his security post in the near future, because it is considered incompatible with his new job in the Secretariat.

Son of a Stavropol railway worker, Andropov worked in the Foreign Ministry before taking the job as Hungarian envoy in 1954.

On his return from Budapest in 1957, Andropov headed a key Central Committee department overseeing relations with other governing Communist parties. In this job, he was closely involved in handling the early years of the Sino-Soviet split and in dealing with Eastern Europe.

After becoming a full Central Committee member in 1961, Andropov was appointed as one of that body's 11 secretaries in 1962 and served in that post until he moved to the KGB in 1967.

The Central Committee Secretariat directs the Communist Party's machinery, while the Politburo is the party's supreme policy-making body.

When he was appointed to head the secret police, Andropov was seen as the party's choice to oversee the security services and keep them under political control. He has served in the Politburo since 1973.