Abstract: In this paper, a comparison analysis was made based on the investigative data of 70 plots on the relationship between the site factors and the biomass of the organs in Cunninghamia lanceolata plantation of Xijiang river district, an estimative model was related to the biomass and the site factors was established; and the scope values of the fitter site conditions to cultivate plantation of Cunninghamia lanceolata for this district and the biomass of stemwood depending upon the relation with the biomass of the branches and roots were given. A theoretical basis for to select and make a plan for Cunninghamia lanceolata planting-site, and its management was provided for Xijiang river district.

Key words: Cunninghamia lanceolata Plantation biomass, Site factors, Estimative model