Abstract: The Populus bonatii forest is a type of deciduous broad-leaved forests in Yunnan.In this paper, the structure of the P.bonatii forest in Xujiaba region of the Ailao Mountains was described according to the data obtained from field investigation.Based on a stem analysis, the growth regularity of tree height, diameter at breast height(D.B.H.) and stem volume were studied, and an additional analysis on the presence of heartwood-rot was also made. Through a diversity analysis on tree species in different strata of the forest by referring to the stocking density, biological characteristics and suitability of each species, the successional trend of the P.bonatii forest was discussed, and the direction of succession in the near future was outlined to search the efficient ways of recovering the evergreen broad-leaved forest.