Yi, ethnic group of Austroasiatic origin living largely in the mountains of southwest China and speaking a Tibeto-Burman language. The Yi people numbered more than 7.5 million in the early 21st century. Their principal concentrations were in Yunnan and Sichuan provinces, with smaller numbers in northwestern Guizhou province and in the northern part of Guangxi Zhuang Autonomous Region. Almost two-thirds of the Yi live in Yunnan province. The Yi language is spoken in six relatively distinct dialects. Among lesser minorities within the Yi language group are the Lisu, Naxi, Hani, Lahu, and Bai.
The traditional Yi culture includes a hoe-based agriculture, livestock herding, and hunting. A caste system formerly divided the Yi into three groups. The Black Bone Yi, the ruling group, were apparently descended from a people that originated in northwest China. The far more numerous White Bone Yi and the Jianu (“Family Slaves”) were formerly subjugated or enslaved by the Black Bones. The subjugation of the White Bones and the Jianu was ended by the Chinese government in the 1950s. The White Bones have spread over the highlands of Yunnan and Guizhou, while the heartland of the Black Bones lies in the great and lesser Liang Mountains southwest of the Sichuan Basin.