Abstract: 1. Under the background of tropical monsoon climate, this region situated in the Northern edge of tropics is influenced by the South-western monsoon in the dry season, and because of the Massenerhebung (mass elevation) effect, it forms the ecological series of seashore xerophytic thorn shrub, savanna, tropical semi-deciduous monsoon forest, tropical evergreen monsoon forest, tropical mountain rain forest and mossy forest. It is an epitome of the distribution of vegetation types in Hainan Island and is a good base for science research, practice and preservation and development of rare species in our country.2. Analysis of every community showed that the vegetation in Jianfengling possesses the character of tropical rain forest but in vertical structure, it is inferior to typical tropical rain forest. The vegetation types change with the increase in altitude and the change of environmental condition and obey the principle of vertical distribution in south-eastern Asian mountains.3. The point-centered quadrant method may be used for tropical vegetation and we have obtained certain results by using it. Representative species that can represent various vegetation types can be found in the tropical complex community through I. V. (Important Value). It is very valuable for the study and classification of tropical forests.