Abstract: The soil fertilities of Chinese fir (Cunninghamia lanceolata) plantations with different generations are studied through investigating the plantations with different generations,ages and site conditions.The results showed that successive planting results in significant soil fertilities decline of different-aged plantation.As planting generation increases,soil aggregate,non-capillary pore,capillary pore,moisture capacity,maximum moisture capacity and nutrients of different aged plantations decrease,whereas the rate of structure fragmentation and volume of soil increase.The soil fertilities of Chinese fir plantations become degraded after successive planting.