Abstract: It is usually difficult to trace the diachronic development of languages of minority ethnic groups due to insufficient written materials but local annals, fortunately, can provide rich language resources for such studies from the diachronic perspective. Annals of Pu'an Prefecture compiled during the reign of Emperor Qianlong (1736-1796) record rich Yi language materials of various categories. Carefully collecting and categorizing these materials are of great value for investigating the inheritance, development and evolution of the Yi vocabulary and grammar in a relatively long historical process.

Key words: Annals of Pu'an Prefecture of Emperor Qianlong, material of the Yi language, diachronic comparision