Abstract: In August 2022, permanent sample plot with 100 m×100 m were established in main distribution area of Castanopsis eyrei at altitude of 705 m, 827 m and 974 m in evergreen broad-leaved forest in Wulingkeng of Baishanzu National Park, Zhejiang province. Investigations were carried out on population of C. eyrei. The result showed that the population of C. eyrei was stable and had strong regeneration ability from the view of diameter class structure. Small, medium, large, and over-mature trees were contagious distribution in two sample plot except over-matured trees randomly distributed in one plot. The aggregation degree gradually decreased from small trees to medium trees. At ages I to III, the population of C. eyrei had higher life expectancy, and gradually decreased with increase of age. Comparison on population density of C. eyrei in three sample plots demonstrated that the smaller density, the higher average life expectancy of the population. The population survival curve of C. eyrei conformed to Deevey-II type, indicating that the mortality rate at each age class was similar.