The tree species structure optimization for Hunan State-own Wugang Forest Farm was made by employing objective planning model, and an ideal tree species structure was turn out, and then the informative entropy value and relative information entropy value were calculated to evaluate the forest fram's tree species structure stability. The resuls show that the informative entropy value of the tree species structure changed slightly from 1990 to 1999, and were less than the ideal value, and the existing tree species structure in this tree fram is under over orderly state, i.e. the artificial inter...