This paper, using nearly 50 years of meteorological data from four national weather stations of Hulunbeier grassland, analyzes the impact of the changes of temperature, precipitation and evaporation on grassland degradation, the results show that: temperature and evaporation increased significantly and precipitation changed slightly in the study area, available water reduced, leading to even more drought. The trends of climate warming and drying are one of the main causes of grassland degradation in Hulunbeier.