Abstract: The plant species and diversity are very abundant in Daqinggou forest plant community , it’s about one third of total species in Inner Mongolia Autonomous Region. Ecological dominance , species diversity and evenness of community are calculated by Simpson index , Shannon2Wienner index and Evenness index individually. The results are as follows : owing to the Daqingou forest plant community is a intrazonal community type , from bottom of ditch to top , difference of microclimate and environment gradient are significant . Because comprehensive effects of trees , shrubs and grasses , difference of species diversity in various communities and in environment gradient is not very significant , that may be results of special forest community adapts azonal environment in long time , that give us some interesting inspiration to improve environment around Daqinggou district .