Spatial patterns of plant species diversity,plant functional diversity and plant biomass and their relationships with environmental factors in Aerjin Mountain Nature Reserve (AMNR) of Qinghai-Tibetan Plateau were examined in this study.The results indicated that alpine steppe was the major vegetation type in high altitude areas of the southwestern AMNR,alpine wet meadow and alpine steppe were the major vegetation types in low altitude areas of the northeastern AMNR.The vegetation types in middle altitude areas of the northwestern AMNR and low altitude areas of the southeastern AMNR were mainly alpine desert.