Abstract: Combined theoretical analysis with actual tests,a new prediction method(L-PRM) for stand diameter distribution is presented. The method takes the distributed law of different trees in stand as a question of biological interpopulation distribution,and stand diameter distribution is expressed by means of the famous logistic equation──interpopulation dynamic model.The prediction can be made by the two-point recovery and difference restoration.The results proved to be satisfactory after the examination in Cunninghamia lanceolata forest.