Abstract: According to the data of investigation, the species and community types of mangroves in Dongzhai and Qingland harbours of Hainan Island and their distributions are expounded.It will be pricise to reflect natural distribution in the estuary region if the distribution of species in mangroves is described in the way of two dimensional space, i.e.the direction of tideflow as vertical, the direction perpendicular to it as horizontal.By the analysis of climatic difference and introduced species, it is concluded that the narrow-distributed and hot-like tropic species can be introduced to the north of tropical seabeach.Besides those mantioned above, it is summed up that what kind of land is suitable for some mangrove afforestation and point out that diking mangroves for breeding pond and clearing planting crops is harmful.