Abstract: Biomass and soil organic carbon dynamics of Cryptomeria fortunei plantations at 5, 10, 17, 22 and 26 years-old were studied at Pengzhou County, Sichuan Province, employing volume-biomass method and soil profile investigation.Biomass of C.fortunei trees increased with age increasing, but such increases were nonlinear.Carbon storage of C.fortunei was estimated at 19.8, 67.5, 85.8, 162 and 275 t/hm² in 5, 10, 17, 22 and 26 years-old plantations, respectively.Soil organic carbon also increased with tree age increasing.Organic carbon in soil profile decreased in the order of 0-10 cm > 10-30 cm> 30-50 cm> 50-70 cm, with most distributed within the top 50 cm.The A-0 to C layer ratio of soil organic carbon decreased with increased tree ages;it was sequentially 14.8, 9.68, 8.85, 5.27 and 3.86 for 5-26 years old plantations mentioned above, indicating the contribution of tree root system to soil carbon accumulation in the deeper soil layers.Soil organic carbon storage was 80.4, 106, 126, 164 and 210 t/hm² in 5, 10, 17, 22 and 26 years-old plantations.These findings indicated that C.fortunei plantations have a vast carbon storage and play an important role in soil carbon sequestration.