Abstract:The total uptake of the ten nutrient elements of 25—28 years old Cunninghamia lanceolata in Guangxi Longsheng county Lilao forest region were 139.278 kg/ha·a, 19.5% of which(was retained by the tree layer, and 48.1% and 32.4% of which were returned to the soil through litter and rain leaching respectively. The ratio of annual return to annual uptake of N, Mg, S, Mn, Zn, B was more than 0.8 for N, Mg, S, Mn, Zn and B, was 0.72—0.74 for P, K, Ca, and was under 0.7 for Cu.The main factors which affect the biocycling of nutrient elements on the tree layer of Cunninghamia lanceolata plantations were the soil depth and the nutrient concentration in soil, and the diameter and height of the tree, etc.