Abstract: In this paper, The major plant communities and its vertical distribution in Guhsiang region of southeastern Tibet are describted as follows: 1. In accordance with the conditions of coefficient of similarity of the species between narrow belts, the vertical vegetational distribution on the southern and northern slopes of Guhsiang region may be divided into eight zones (fig. 1). 2. The seven types of plant communities are describted. The relationships between the distribution of plant communities and humidity-warmth conditions are shown (fig. 2) 3. Being affected by different humidity-warmth conditions, the differences between vegetation zones in numbers of species are rather well-marked (table 3).