Abstract:The genus Acer has 58 species, 5 subspecics and 24 varieties in Hegnduan Mountains. There are 148 species of Acer in China. The species of Acer in Hengduan Mountains occupy 39.2% of the total species of China and the region is the largest distribution center of the genus in modern times. The genus there has 27 endemic species which occupies 46.55% of the total species of the genus in the region. It shows that the differentiation of species of the genus in the region is taking place actively. 14 sections of the genus Acer of China are divide which include primitive, intermediate and advanced forms and all the sections can be found in the region. And there is one endemic section there.