The Dalai Lama, the spiritual leader of Tibetans, said the increasing number of self-immolations by monks and nuns in Sichuan province are because hard-line Chinese officials have created a "desperate" situation, a report by the BBC said.
More than 10 Tibetans have set themselves on fire this year, with the latest dying last week.
The "cultural genocide" term is some of the strongest language used by the Dalai Lama, who has been living in exile in northern India since fleeing Tibet after the Chinese takeover in the late 1950s.
Beijing considers the Dalai Lama a terrorist and blames him for fomenting independence movements within Tibet, as well as encouraging self-immolation.
The Dalai Lama was speaking to around 80 journalists at a news conference organized by Free Press Association of Japan in Tokyo when he used the term "cultural genocide."
"Chinese communist propaganda creates a very rosy picture. But actually, including many Chinese from mainland China who visit Tibet, they all have the impression things are terrible," he said.
"Some kind of policy, some kind of cultural genocide is taking place," the BBC reported.
The official Web site of the Dalai Lama, however, didn't mention use of the words "cultural genocide."
He questioned whether Chinese authority over Tibet is "liberation or occupation" and challenged journalists to visit Tibet to see for themselves the situation.
"These are desperate acts by people seeking justice and freedom," he said.
"Chinese leaderships should take this seriously and try to solve the people's grievances. They should accept the reality, reality is that there is human rights problem in Tibet, religious and cultural oppression is going on and there is environmental destruction in Tibet."
Much of the protest has centered in Sichuan province, in particular near the Kirti Buddhist monastery. The area around the monastery Kirti Gompa, founded in 1472 on the edge of Ngaba or Aba City, has been tense since Rigzin Phuntsog, a monk, set himself on fire and died in March.
Many Tibetans in Sichuan, a province directly east of Tibet, are angry about what they see as a ploy by Beijing to move ethnic Han Chinese into the majority Tibetan areas of Sichuan. Tibetans say it is a direct policy by Beijing to make Tibetans a minority in their own land.
In March 2008 four protesters in Ngaba were shot by security forces acting to contain anti-China demonstrations in the Tibetan regions, including in Lhasa in Tibet.
Last week, U.S. State Department spokeswoman Victoria Nuland said the United States has "repeatedly urged the Chinese government to address its counterproductive policies in Tibetan areas that have created tensions."
In July, Vice President Xi Jinping, the man believed to be China's leader-in-waiting, said he will "smash" any plan to undermine Tibet's place within China.
He made the statement during a major trip to Lhasa, the capital of Tibet, where he and his entourage of nearly 60 senior central government delegates celebrated China's takeover of Tibet in the 1950s.
Xi said China and Tibet "should thoroughly fight against separatist activities by the Dalai clique by firmly relying on all ethnic groups ... and completely smash any plot to destroy stability in Tibet and jeopardize national unity."
The term "Dalai Lama clique" often is used by official Chinese media to describe any group Beijing believes to have tendencies toward Tibetan independence.
The state-run Xinhua news agency reported last week's self-immolation was "masterminded and instigated by the Dalai Lama clique."
Chinese Foreign Ministry spokesman Hong Lei said the Dalai Lama, by not condemning self-immolations, was "playing them up and inciting others to follow," Xinhua reported.
But in April, after several self-immolations, the Dalai Lama issued a statement calling on all sides to remain calm.
"I am very concerned that this situation if allowed to go on may become explosive with catastrophic consequences for the Tibetans in Ngaba," he said in a written statement.
"In view of this I urge both the monks and the lay Tibetans of the area not to do anything that might be used as a pretext by the local authorities to massively crackdown on them. I also strongly urge the international community, the governments around the world, and the international non-governmental organizations, to persuade the Chinese leadership to exercise restraint in handling this situation. "
The Dalai Lama has begun a visit to Mongolia.