The Yi ethnic group, with a population of 7,762,286, is mainly distributed over the provinces of Sichuan, Yunnan and Guizhou, and the Guangxi Zhuang Autonomous Region. There are more than one million Yis in Sichuan Province, and most of them live in an area south of the Dadu River and along the Anning River. Traditionally, this area is subdivided into the Greater Liangshan Mountain area, which lies east of the Anning River and south of the Huangmao Dyke, and the Lesser Liangshan Mountain area, which covers the Jinsha River valley and the south bank of the Dadu River. There are over a million Yis in the Liangshan Yi Autonomous Prefecture, which holds the single largest Yi community in China. Yunnan Province has more than three million Yis, most of whom are concentrated in an area hemmed in by the Jinsha and Yuanjiang rivers, and the Ailao and Wuliang mountains. Huaping, Ninglang and Yongsheng in western Yunnan form what is known as the Yunnan Lesser Liangshan Mountain area. In Guizhou, more than half a million Yis live in compact communities in Anshun and Bijie. Several thousand Yis live in Longlin and Mubian counties in the Guangxi Zhuang Autonomous Region.

Most Yis are scattered in mountain areas, some in frigid mountain areas at high altitudes, and a small number live on flat land or in valleys. The altitudinal differences of the Yi areas directly affect their climate and precipitation. Their striking differences have given rise to the old saying that "the weather is different a few miles away" in the Yi area. This is the primary reason why the Yis in various areas are so different from one another in the ways they make a living.

The Yi areas are rich in natural resources. The Jinsha River running through Sichuan and Yunnan and its tributaries surging through the Yi areas in northern and northeastern Yunnan are enormous sources of water power. The Yi areas are not only rich in coal and iron, but are also among China's major producers of non-ferrous metals. Gejiu, China's famous tin center, reared the first generation of Yi industrial workers. Various Yi areas in the Greater and Lesser Liangshan Mountains, western Guizhou, and eastern and southern Yunnan abound in dozens of mineral resources, including gold, silver, aluminum, manganese, antimony and zinc. Vast forests stretch across the Yi areas, where Yunnan pine, masson pine, dragon spruce, Chinese pine and other timber trees, lacquer, tea, camphor, kapok and other trees of economic value grow in great numbers. The forests teem with wild animals and plants as well as pilose antler, musk, bear gallbladders and medicinal herbs such as poris cocos and pseudoginseng.