THE DARK SIDE OF CHINA; 21 years in prison did not embitter Chue

CHUE Shu is one of the Kumbum Lamasery's ''living buddhas.'' At 48, he has already spent 21 years working and living in the Qinghai hydroelectric ''factory'' as a religious and political prisoner.

He was sent there in 1958 as part of the purge that followed an unsuccessful uprising by the people of Tibet against China's established Communist government.

Pronounced a living buddha at age two, Mr. Chue later traveled to Tibet to study. When he returned to Kumbum at the age of 23, the Chinese government declared such activities ''counterrevolutionary'' and sentenced him to life in a lao-gai, or labor camp.

Inside the camp, he was not allowed to wear the traditional scarlet robes or saffron cap of his office, nor practice his religion. Instead he was instructed in medicine and spent his time tending to sick inmates.

Ironically, it was his time in Tibet that saved Chue from the most sinister aspect of the lao-gai system: the constant ''struggle sessions,'' in which prison authorities and fellow inmates break down a prisoner by citing details of his past that they feel prove his depraved character.

''No one was abused,'' Chue says. ''And my suppression was not great. I was not struggled against extensively. Because I had studied in Tibet, the local people knew little of my background.''

Traditionally, such sentences were for life, but 21 years after he was imprisoned, Chue benefited from the more moderate policies of the current Chinese leader, Deng Xiaoping.

He was released from the camp at age 43, returned to the lamasery, appointed its head, and eventually became a member of the Chinese People's Political Consultative Conference - a largely token organization designed to provide the Communist leadership with access to the views of noncommunists, Hong Kong community leaders, returned Taiwanese, and religionists.

Today, once again wrapped in the scarlet robes of the living buddha, Chue Shu displays no bitterness toward his oppressors. And in this he reveals the lasting success of the methods used in China's lao-gai.

''It was the court that said I had committed counterrevolutionary crimes that redressed my case. It is not very easy for the courts to correct mistakes,'' he says.

''I am happy toward the Communist Party. I believe the Communist is a party that seeks truth from facts,'' he said, using the very dictum of his temporal master, Deng Xiaoping. Chue shocks his listener in the completeness of his forgiveness - and reform.