Nuosu or Nosu, also known as Northern Yi, Liangshan Yi, and Sichuan Yi, is the prestige language of the Yi people; it has been chosen by the Chinese government as the standard Yi language and, as such, is the only one taught in schools, both in its oral and written forms. It was spoken by two million people and was increasing ; 60% were monolingual. Nuosu is the native Nuosu name for their own language and is not used in Mandarin Chinese, though it may sometimes be translated as Nuòsūyǔ.

Chuxiong Yi Autonomous Prefecture is an autonomous prefecture located in central Yunnan Province, China. Chuxiong has an area of 29,256 km2 (11,296 sq mi). The capital of the prefecture is Chuxiong City.