Abstract: This paper reports the result of influences to the growth of Chinese fir caused by adopting six various planting densities of 240,167,122,94,74 and 60 trees/mu. The results demonstrate that variation in planting density has an obvious influence to diameter growth (breast diameter) of the trees.It usually increases as the planting density decreases.But there is a limitation that the diameter-growth will not increase in proportion to the rule of variance of planting density,after the trees in a plarltation of 60 trees/mu have been planted for 15 years. There is no rule derivable from the influence of variance of planting density to the growth in length of Chinese fir.The duration in terms of years for the increase of crown width and length prolongs as the planting density decreases. Growth of individual tree in terms of volume increases as the planting density decreases.The biggest volume increment per unit area belongs to the plantation of 122 trees/mu,reaching 21.1575m~3. The result of our experiment shows that the most suitable planting density for Chinese fir is 122 trees/mu and thinning is not necessary for this plantation.