The man set himself alight along the main street of Ngaba which sits on the Tibet plateau in a Tibetan-inhabited area of China’s Sichuan province, the London-based Free Tibet said in a statement.
Local government officials in the town, known as Aba in Chinese, were not immediately available for comment.
Security personnel quickly extinguished the flames and took the man away in a security vehicle, the statement said.
He was believed to be still alive, although his upper body was badly burned, it added.
More than 40 people have set themselves on fire in recent months in Tibetan-inhabited areas of China in protest at repressive government policies, the group said, with most incidents linked to monks or former monks of Aba’s Kirti monastery.