According to the evaluative data of forest biodiversity variation in China from 1973 to 1998, not only the gray model GM( 1,2), but also the status spatial characterization model with the optimal control model for forest biodiversity variation is developed by using some mathematic approaches and knowledge in economic cybernetics. Furthermore, the structural characteristics of forest biodiversity variation are analyzed. The paper points out that the variation of forest biodiversity is instable, but it can be controlled and known certainly. The close-loop feedback controlling and the optimal controlling are also existent. That is to say, the preestablished targets of forest biodiversity variation can be met by adjusting the policy’s variables, thus alleviating the pressure of forest biodiversity. The variation of forest biodiversity can be shown by the pressure index of variation. This paper finally shows that when the pressure index of forest biodiversity is a constant 100, the optimal movement curves ar According to the evaluative data of forest biodiversity variation in China from 1973 to 1998, not only the gray model GM (1,2), but also the status spatial characterization model with the optimal control model for forest biodiversity variation is developed by using some mathematic approaches and knowledge in economic cybernetics. Furthermore, the structural characteristics of forest biodiversity variation are analyzed. The paper points out that the variation of forest biodiversity is instable, but it can be controlled and known certainly. The close-loop feedback controlling and the optimal That is to say, the preestablished targets of forest biodiversity variation can be met by adjusting the policy’s variables, thus alleviating the pressure of forest biodiversity. The variation of forest biodiversity can be shown by the pressure index of variation. paper finally shows that when the pressure index of forest biodiversity is a constant 100, the optimal movement curves ar