Hainan Island is a part of tropical China. The differentiation of temperature within Hainan Island is not significant, but that of rainfall distribution is quite remarka-ble.According to the principle of climatic division the main indices of climatic division in tropic should be given way from the heat (temperature) to the moisture (.rainfall, rainy, season......).On the other hand, although the climate of Hainan Island is belong to tropical, but it is modified deeply by the monsoon, as the northen part of this island there appears a the Island, play an important role of climate divisionHence, moisture, temperature and topography of Hainan are chosen as the three main indices for the division work simultaneously.The climatic division of Hainan should be divided into eastern side and the western side by the parameter of water balance; also divided into nortern part and southern part by the thermal parameter (temperature), they made a cross shape over the Island ; again, divide the mountain and the, lower flat land (corespondant of wind condition i which made a circle shape. By mean of that, the regional division of Hainan may be after a model (fig. 1) divided into 8 division parts as follow:1. XE part seashore plain climate, more cool, windy and more wet. such as in Wenchang. The shore lin forest belt should be built for agriculture.2. XW part seashore plain climate, more cool, windy but more dry, such as Ling-ao.3. XE part hill district and basin climate, more cold and wet in winter, such as Tunchang.4. XW part mountain and hill district and basin climate, occasionally fierce cold winter. It is harmful to rubber tree cultivation, such as in Baisha.5. SE part seahore plain climate, more windy, more warm, and wet, such as Qiong-hai. Shore line forest belt should be built up for agricuture.6. SW part seashore plain climate, more warm, fierce dry, such as Dongfang.7. SE part of mountain and hill district, valley and basin climate; more wet and warm, such as Baoting. It is favour for rubber and other tropical crops, as an old district of tropical agriculture.8. SW part of mountain and hill district basin climate, more warm and dry, such as Ledong. There are many small areas with more favorable local climate for rubber here and there. It is a new region for the cultivation of rubber and other tropical crops or forest.