Abstract:The effect space of tree competition in the artificial mixed forest of Cunninghamia lanceolata and Tsoongioden odrum in Dong’an Forestry Farm of Jian’ou, Fujian Province, was divided into two parts, inside radius and outside radius. The interspecific and intraspecific competition intensities of C. lanceolata and T. odrum were analyzed by using Hegyi’s Individual Tree Competition Index model. The results showed that all competition intensities of C. lanceolata, including intraspecific competition and interspecific competition, reduced with increasing of tree diameter classes in the both competition radiuses. The order of competition intensity was followed as intraspecific competition intensity of C. lanceolata in the inside radius > interspecific competition intensity of T. odorum in the inside radius > intraspecific competition intensity of C. lanceolata in the outside radius > interspecific competition intensity of T. odorum in the outside radius. The competition intensity in the forest was predicted by the simulation model, which indicated that some management measures should be conducted to decrease the competition intensities of C. lanceolata before the diameter at breast height of C. lanceolata up to 36 cm.