Abstract: The relationship between main vegetation types and climate factors in Inner Mongolia was analyzed by using up to date vegetation map,statistics,modeling and spatial simulation of regional climatic factors under the support of GIS.The feasible climatic range of spatial distribution of plant communities was derived from overlaying vegetation map and climate maps.The results showed that the vegetation distribution was obviously in accordance with climate.On the one hand,all the types,not only zonal vegetation,but also mountain,sandy land and low land communities changed gradually from east to west due to the distance to oceans,with a zonal differentiation,Precipitation played an important role in determining this regulation.On the other hand,latitudinal replacement of plant communities occurred with the change of temperature from north to south.In addition,temperature was also the key factor controlling the spatial distribution of vegetation types,such as meadow,steppe,shrub and low land communities on the east and west sides of Daxinganling Mountains.