Abstract:The method and significance of analysis of the plant species for urban afforestation is studied by analyzing the following three aspects:the structure of plant species,the floristic components and the aesthetical pattern of the plant species in, Hainan cities.The important value of plant species for urban afforestation is described by taking the sum of the relative density,the relative presence and the relative coverage of the plant species, and the relationship between the characteristic of the artificial vegetation of urban afforestation and region is also analysed by studing floristic components of plants in cities.However,it is pointed out that the principle of urban afforestation is right in Hainan,and prominence should be given to the theme,and various patterns of the plants should also be embellished for the rational distribution of the afforestation plants in Hainan.