Abstract:The characteristics and sucession pattern of alpine shrub lands under different grazing intensities are studied with methods of diversity analysis, clustering and principal component analysis in this paper.The results of diversity analysis show that plant diversity reaches the maximum in the C-group of pasture. The clustering analysis results show that when the correlation coefficient R≥0.90, the plant species taking importance value as characteristic are grouped into 10 types, belonging to constructive plants, dominant plants, and associated plants of different successive phases of plant communities respectively. Principal component analysis has shown that 5 communities of alpine shrub lands under different grazing intensities are grouped into 3 types. The A and B groups of pastures belong to plant communities of 2-layer structures taking shrub and forbes as dominant plants and, the C group of pastures belongs to plant communities taking shrubs as constructive plants and taking forbes and grazing-resistant sedges as polydominant plants and, D and E groups of pastures belong to plant communities of 3-layer structures taking shrubs as polydominant plants.