It's in the Yi Autonomous Prefecture of Liangshan, Sichuan Province, which has the largest community Yi of China. Most of them live in mountainous regions, and a few in the plains and valleys. Mountain farmers, they practice agriculture, associated with hunting and farming. The Yi are divided into two castes: the Black Yi (nieso or nosu) and Yi Blanc (or jjisse Jiho). The Black Yi form a sort of aristocracy dominating the White Yi who have the status of serfs and slaves of some. The second caste is subdivided by an internal hierarchy. It is through their style of dress that can distinguish Yi Yi Black White. The social and political structure of the Yi was subjected to a rapid transformation under the aegis of Chinese Communism.