Abstract: The alpine cushion vegetation is a peculiar type of the alpine vegetation, Which widely distributes in the Qinghai-Xizang plateau, range Tianshan and the Eastern Pamir of China, and developes best in Xizang. In this paper, the problem of the correct differentiation of the alpine cushion vegetation are discussed, in addition, Some Characteristics of the environment, distribution and composition of the alpine cushion vegetation in Xizang are analysed and discussed. The authors suggested that the Xizang plateau is an another original center of the alpine cushion vegetation besides the Pamir plateau according as authors had analysed the basic characteristic of the alpine cushion vegetation in Xizang. The following 5 main formations of the cushion vegetation of the Xizang are summarized: Form. Androsace tapete, Form. Arcnaria bryophylla, Form. Arenaria pulvinata, Form. Thylacospermum caespitosum and Form. Chionocharis hookeri.

Key words: Xizang, Alpine Cushion vegetation, Cushion plant