Abstract:The genus Rhododendron plays an important role in the Xizang floristic and vegetational formation. There are over 170 species (not including subspecies , and varieties). It stands first on the list of the largest genera of the Tibetan Angiosperms. The abundance of its species is next to that of Yunnan only. The species of Rhododendron in Xizang belong to 2 subgenera: 1. Subgen. Hymenanthes may be classified into 22 subsections 17 of which are found in Xizang. 2. Subgen, Rhododendron, out of a total of 34 subsections 22 are found in Xizang.