Simulated experiment on climate changing was conducted in Haibei Prefecture,Qinghai Province,from June to August 2015.Effects of increase of air temperature(2℃) and precipitation(20%) on species diversity and community stability of Stipa purpurea was studied after removal of dominant species in the Alpine Meadow.The results showed that increase of air temperature and precipitation,and their interaction had no significant effect on plant height,coverage and aboveground biomass.Increase of air temperature significantly increased the diversity indices of Shannon-Wiener,uniformity indices of Simpson and dominance indices of Pielou.Increase of precipitation significantly increased the diversity indices of Shannon-Wiener,Simpson and Pielou.There was a positive correlation between coverage indices and plant species diversity,and between coverage indices and dominance indices.