Abstract: Lastly, works haye been done in the comparative study on the features of physiognonly and structure with tropical cquatorial rainforest. The discussion and comparison show that the floristic component of the forest oil horizontal distribution there are some species are the preyalence everywllere, others due to the cvolution and spread of specics, new species cvolve, old species die out or come to occupy more rcstricted areas, and according as the different local geo- morphy, soil, climate are formed diversity society, from the further constituted mosaic. these society and mosaic in the same a forestland are striking too. The vertical structure of forest consists of the seven layers in natural forest, and the species of structure each layer, D layer is more than others layer of which appears that have the major independent charactcr interlayer relationship. The trees layer, the shrubs layer, the herbaceous layer and the grounds layes are fundamental synusia and they make up the skeleton in forest structure.

Key words: Xishuangbanna