Abstract: The stand density control diagram for Cunninghamia Lanccolata is made in accordance with the theory used in Japan, by combining the practical growing condition of the above-mentioned species in China and collecting 992 stand plots of seedling and 662 plots of stand from cuttings. The diagram is consisted of the full density curve, equivalent height curve, Curve equivalent diameter at breast height, density control curve as well as the natural thinning curve. According to the growing characteristics of the stands of this species, the initial thinning density curve and the minimum reserved density curve after thinning are determined. The diagram may be used for many purposes. It can be used for thinning, forst inventory, prediction of growth as well as the design for sylvicultural practices, etc. The accuracy of the diagram after testing is normally over 90%. It can be generally used for Cunninghamia Lanceolata in China.