Abstract:In order to investigate the changes in tree species composition and biomass storage of degraded forests, we selected the evergreen broad-leaved forests in Ailao Mountain, Yunnan Province, southwest China were selected as the objects, and the forest community structure, tree species diversity and biomass changes were compared at different succession stages. The results showed that the number of families of tree species decreased first and then increased from early successional stage (ES) to late successional stage (LS), while the numbers of genera and species gradually increased. Moreover, the Margalef richness index, Simpson dominance index, Shannon-Wiener diversity index, and Pielou evenness index all increased with succession process. The tree biomass showed an increasing trend, which at ES and middle successional stage (MS) were 9.87% and 65.98% of that at LS, respectively. Furthermore, the tree diversity index had significant positive correlation with the total biomass at plot level (P<0.05). Therefore, it was suggested that with the succession process, the growth of trees and the tree species diversity were the main factors affecting tree biomass storage, and the forest restoration in the Ailao Mountains was relatively slow because of moist and cold climate.