The grassland in Inner Mongolia is an important ecological security guarantee in northern China,the ecological environment in the area is extremely sensitive to climate change.Studying the characteristics of extreme climate events of the area can promote the understanding of the response of grassland to climate change.Based on the relative humidity index and nonparametric percentile method,combined with linear trend method,Mann-Kendall mutation and cumulative anomaly test,we analyzed the characteristics of the change in temperature,precipitation,and the extreme climate events in four different grassland areas in Inner Mongolia(Dolun,Xilinhot,Hailar and Siziwang Banner)from 1955 to 2015. The results indicated as follows:(1) The annual average temperatures of the four regions were significantly increased at a rate of 0.40-0.47℃·(10 a)-1,and presented asymmetric trend,the rising rate of minimum temperature in Duolun,Xilinhot,Hailar and Siziwang Banner were 1.61,1.86,2.73 and 1.65 times higher than those in correspondenceof the maximum temperature,respectively,and the rising rates in spring and winter were higher than those in summer and autumn. (2) The annual total precipitation in Duolun,Hailar,Siziwang Banner and Xilinhot were 381.6 mm,350.5 mm,318.6 mm and 283.6 mm,respectively. Although the number of precipitation days was increased significantly,the precipitation in Dolun and Xilinhot was slightly decreased,while it was slightly increased in the other two regions. (3) The frequency of extreme high temperature events was increased significantly,while the extreme cold events was decreased significantly. (4) In the past 60 years,the climate in the four regions has been warming and drying,among which the extreme drought events in Xilinho thad the highest frequency while Siziwang Banner was dominated by moderate drought.After 2000,the frequency of drought events in the four regions was increased significantly,this may be due to the significant increase in temperature and potential evapotranspiration,while the precipitation did not change significantly.