The distribution features of biomass and carbon storage of 43-year-old Cyclobalanpsis glauca mixed forest in Yongshun county, Hunan province, were studied. The biomass of tree layer and under-storey was measured by the average standard method and plot harvest method, and carbon contents by potassium dichromate-hydration heating method. The results showed that biomass per unit area of the mixed forest was 320.03 t/hm². The order of biomass per unit area from large to small was tree layer, litter layer, shrub layer and herb layer. Carbon storage per unit area of the mixed forest was 389.43 t/hm², which included vegetation layer (249.02 t/hm²) and soil layer (140.41 t/hm²). As increasing of soil depth, the carbon storage decreased. The average volumes per plant of Cyclobalanpsis glauca, Castanopsis fargesii and Cunninghamia lanceolata were 0.156 1, 0.291 2 and 0.296 0 m³ respectively, while the average carbon storages per plant were 103.85, 99.15 and 97.90 kg respectively. Cyclobalanpsis glauca was slow-growing woody species with large wood density, its average individual volume was only half of Castanopsis fargesii's and Cunninghamia lanceolata's, but both its average biomass per plant and average carbon storage per plant were higher than the latter two. It showed that the ability of carbon sequestration of tree species wasn't entirely determined by the growth rate. This finding provided a new option of tree species for ecological forest.