Abstract: The state vectors are used to describe the dynamical variables for forest resources in this paper. First, by using the data obtained from CFI in Guang-xi province, the transitional matrices of probability for forest volumes and areas and the dynamic forecasting models of structure for forest resources are built. Through standard transformation, the transitional matrices proper for the equivalent intervals of time are attained. Secondly, the methods of Kalman filtering are used to forecast the dynamics of structure for forest resources in Guangxi, it shows excellent results.