Critics say there is no real autonomy in Tibet, where Buddhist monks and nuns loyal to the region's exiled god-king, the Dalai Lama, have been jailed and sometimes tortured.

But China defends its rule, saying life has improved for countless "serfs" emancipated after a failed uprising which led to the Dalai Lama fleeing into exile in India in 1959.

"Before implementing democratic reforms, Tibet was under the dark serf system. Only today are Tibetans true masters of their own house," Foreign Ministry spokesman Qin Gang told reporters.

"Tibet is moving from being basically stable to long-lasting stability," Qing said, adding that China brooked no foreign interference in Tibet, describing it as an internal affair.

Tibet's gross domestic product surged to 21.154 billion yuan ($A3.45 billion) in 2004 from 327 million yuan in 1965, the People's Daily, mouthpiece of the Communist Party, said.

"Only under the leadership of the Communist Party ... can Tibet have today's prosperity and progress," the newspaper said in an editorial.

Tibet has been ruled by the Communists since the People's Liberation Army (PLA) marched into the region in 1950.

The vast, sparsely populated region known as "the roof of the world" was designated the Tibetan Autonomous Region in 1965, a gesture Beijing made to other areas with large ethnic minority populations too to give them more say over their affairs.

The Chinese central government sent a delegation to Tibet's capital, Lhasa, led by Jia Qinglin, ranked fourth in the party hierarchy, for festivities marking the anniversary.

About 23,000 people watched a flag-raising ceremony on the vast square at the foot of the Potala Palace, home of the Dalai Lama before he fled into exile.

Bayonet-carrying PLA soldiers and about 6,000 singing and dancing Tibetans in traditional attire marched past a stand on the square while Jia and other leaders looked on.

Jia shook hands with a group of Buddhist monks and urged them to be "patriotic".

"Tibet has undergone tremendous changes. Tibet has a great potential and a broad prospect for development. Tibet now faces two major tasks: one is development and one is stability," the state news agency Xinhua quoted him as saying this week.

Xinhua said 13 ethnic Tibetans had been promoted to the rank of major general or lieutenant general in the PLA or the paramilitary People's Armed Police.

The London-based Free Tibet Campaign criticised the celebrations as "a major propaganda opportunity for China to promote its version of autonomy".

Some analysts say that, 40 years on, Tibetan society is more fractured than ever, with Tibetans becoming an underclass lacking the skills to participate in Beijing-driven industrialisation.

The Free Tibet Campaign said recent visitors to Lhasa had noticed a visible increase in police presence, following a pattern of stepped up security around other major dates.

Source: SMH.com