Abstract: The characteristics of rainfall and evaporation in different regions in recent 30 years in Hainan Province were researched in this paper according to the weather data in 1974 to 2004 by offered the weather bureau of Hainan Provence and the data of rainfall and evaporation in the weather bureau of Hainan Province which belonged to one chapter of the publication of annals of Hainan Province by published 2005.The results indicated that the rain mostly occurred in the month of 8 to10 and the evaporation mostly occurred in the month of 5 to 7, the evaporation is obviously more than the rainfall in spring and winter and the rainfall is obviously more than the evaporation in summer and autumn except the south and the west which the evaporation is more than the rainfall in most regions of Hainan Province. The results indicated that the average rainfall of one year is more than the average evaporation of one year in east and center and the average evaporation of one year is more than the average rainfall of one year in south, north and west region of Hainan Province.