Abstract: Based on the Cunninghamia lanceolata zone and region,which are divided in 14 southern provinces(regions)accordiog to the Chinese fir research coordinated groups,in 1981 the experimental plantations of Cunninghamia lanceolata were established in Guangxi,Jiangxi,Fujian, Sichuan and Henan Provinces,which consisted of 5 different densities.The measurements of 10 years showed that densities influenced the main growth parameters of trees and wood quality. According to the analysis of timber yield and economic benefit,the optimum initial planting densities for various index classes are determined,i.e.5000 trees per hectare are optimum for the index class of 14-16 in the south and middle zone, and for the index classes of 12-14 in the north zone, 3333 trees for those over 18 classes in the mid zone.

Key words: Cunninghamia lanceolata, Planting density, Economic benefit