Abstract: The succession of the main forest communities in the forest region of the Greater Xingan Mountain has been analysed according to checking of 29 plots which were set up in 1954. It was found that the’ forest dominated by Larix gmelinii was the climax in this region, the forest Pinus sylvestris var. mongolica was the edaphic climax, and the forest Betula platyphylla, Betula davurica and Quercus mongolica were secondary forests respectively. They are evolving towards Larix gmelinii forest.