Abstract: 【Objective】 The effects of altitude gradient on grassland community composition and diversity were discussed in order to provide reasonable suggestions for grassland management and conservation.【Method】 Margalef index,Simpson index,Shannon Wiener index and alatalo index are used to analyze the area with an altitude of 1 500～2 500 m in Liangheyuan Nature Reserve.【Result】 There are 123 species of grasses in Liangheyuan Nature Reserve,belonging to 43 families and 101 genera. AgroPyron cristatum,Taraxacum mongolicum and Geranium Pratense are the dominant species in this area. With the change of altitude gradient,the quantity structure and characteristics of grassland are quite different. The altitude gradient is highly correlated with various diversity indices. Among them,Margalef index,Simpson index and Shannon Wiener index all increase with altitude,but Alatalo index decreases with altitude.【Conclusion】 With the increase of altitude gradient,the quantitative structure and characteristics of grassland communities fluctuate,and the change of altitude gradient has a great impact on the community diversity. Among them,ComPositae,Rubiaceae,Rosaceae and Shikonaceae should be the preferred species for ecological restoration and grassland reconstruction.