Beneath the endless attention of a large gilded statue, monks in rich ochre robes bend aged heads over Sanskrit tablets, chanting in union the prayers of the Feast of the White Moon.

Around them, still as stones, soughly dressed peasants silently tell beads and watch the holy men, as if in anticipation of divine deliverance.

These are Buddhists of the Soviet Union, of a flock who have suffered from repression, a tribulation that in its season has plagued all religions.

Buddhism once commanded and ordered the life of many in this eastern Siberian region of dry plains and sharp, unyielding mountains east of Lake Baikal and north of Mongolia, 3,000 miles by air from Moscow. At the turn of the century, there may have been 10,000 lamas in the area of what is now the Buryat Autonomous Republic. They were centered in about 40 datsans , or Buddhist monastery temples. The lamas found their believers among the Buryats, illiterate, nomadic tribesmen related to the Mongols who roamed the area keeping sheep and cattle, living in teepee-like chyums , and suffering from an infant mortality rate that by some Western estimates may have been as high as 60 percent.

The other principal religions among the Buryats of those times were shamanism (witch-doctoring) and Christianity, which "old believers" of the Russian Orthodox Church brought with them when they emigrated from European Russia beginning in the 17th century.

Today, there are just 28 active monks in Buryatia, elderly men who live and pray in the vast republic's one remaining datsan , a brilliantly painted, pagoda-like building set behind a low monastery fence in the middle of a scrubby plain about 30 miles by road from Buryat capital of Ulan-Ude. A few other doyen lamas who have similarly been "registered" with the state live scattered around Buryatia, an area larger than Norway, and several hundred retired district lamas, similar to lay workers in American Christian churches, are thought to live in the largely rural and isolated parts of the republic.

No one, however, will say how many Buddhists there might be."

We do not keep records on the number of Buddhists," says Jambal-Dorzhi Gomboyev. He is the officially elected head if Soviet Buddhists. His title is bandido hambo lama, president of the Central Religious Board of the Buddhists of the U.S.S.R.

The holy man, a spritely 80, has been head of the Buddhists since the early 1960s, and has been elected every four years by ballot of representatives of Buddhists from around the republic. He is in the unenviable situation of serving two masters. His temporal master is the Soviet government, whose founders savagely suppressed the Russian Orthodox Church to break its power and went on to make war on other sects and religions.

During a recent interview with foreign journalists, he fenced skillfully with his interrogators, giving away very little, deflecting questions in a practiced way.

A reporter cited recent British estimates of 50,000 Buddhists among the 300,000 Buryats, who are now a one-third minority in their Russian-and Ukrainian-dominated republic.

"I have not heard that number," declared the bandido. "Young persons come here in substantial numbers but I have no idea how many. Our constitution makes freedom of religion guaranteed, so this is a very delicate matter. We could not keep records . . . Besides, someone may come today and not come tomorrow."

Soviet law bars the formal teaching of religious practice or thought to anyone below the age of 18. There was not one person identifiably below middle age at the service for the Feast of the White Moon.

"Under the czar there were more monks, but the situation was different then," said the bandido hambo. "Now education is secular, while in former times people went to Buddhist schools."

In all the Soviet Union, there is only one other monastery, in the Chita region east of Buryatia. In addition, there are six young novice lamas being trained in the Mongolian capital of Ulan Bator, less than 300 miles from here. "We are pleased by that," said the bandido.

He then offered a brief history of his own life and hinted along the way how 10,000 lamas became a few hundred during the years of Soviet power, which date here from the early 1920s.

"Our country went through a hard time. You're knowledgeable about that time. The lama community was not uniform. Then, some people could not acept the changes, couldn't understand the new times."

Repression of the Buryat Buddhists began in the late 1920s and culminated a decade later with liquidation of groups of lamas, after an accusation of opposing the revolution and working for the Japanese secret service.

At one point there were no datsans open, the bandido recalled. He was unable to fulfill his holy mission during those years, and found work in a glass factory.

"I functioned, but officially I was not recognized," he said delicately.

During World War II, the Soviet-controlled metamorphosis from a man of holy works to ordinary citizen was completed. He was sent to the front as a soldier, duty which he did not refuse despite his caling.

"This was a defense, a noble cause. There was a motive for my conduct," he said.

Did he slay anyone while at the front?

"I don't know if I have killed someone . . . but I was a good soldier," the lama replied.

After the war, the situation for Buddhists eased. The Ivolgidatsan was built and open worship resumed under the sharp restrictions the Soviets impose on all religious practice. These include a ban on proslytizing and close monitoring of sermons and public statements by religious leaders. Religious leaders frequently speak out in support of official Communist Party doctrine or government views in the manner of such American churchmen as the late Francis Cardinal Spellman Catholic archbishop of New York, or the Rev. Billy Graham.

The government has newer relaxed its vigilant control. In 1973, for example, an internationally known Buddhist scholar and historian, Bidiva, D. Dandaron, was tried and convicted of running an illegal sect for criminal ends under an article of the Soviet code adopted in 1962 during an anti-religious drive by Nikita S. Khrtshchev. Dandaron was sentenced to five years in prison, allegedly for duping members of a Buddhist group he headed which apparently rejected the authority of the official Soviet Buddhist priesthood re represented by the bandido hambo.

TThe pressures on the bandido lama and the flock for which he speaks and acts are clear.

"I want to ask your opinion about the latest development," he said, peering at the correspondents sitting in his conference room at the Ivolgi datsan , sipping his excellent tea and munching his tasty cookies as they probed the mysterious dynamics of religion in an atheist state.

"This is about the neutron bomb, which violates the most sacred right of people to live. Perhaps you are close to the government circles in your country and you could explain about this weapon. . . This is considered the most inhuman and worst weapon ever developed. . ."

And so, he continued for a while in this vein, smoothly expressing the religious concerns of his first master in the service of his second.