Abstract: The characteristics of percolation of different vegetation-soil types and land uses were studied at Jianfengling in Hainan Island, China. Seepage water was collected by a number of open dish collectors from different layers of soil. The relationship between rainfall and seepage water in the area, and characteristics of substance movement in tropical forest ecosystem were analysed. According to two-year observation, it was shown that the annual percolation within 100cm depth of the lateritic yellow soil under the mountain rain forest was 355 mm, equal to 15.9% of the annual rainfall, while in the cinnamon latosol under the semideciduous monsoon forest it had only 30mm which was 1.8% of the annual rainfall. The litter cover and the upper 30cm of surface soil hold the maximum seepage water. The forest has an excellent function of soil and water conservation. The seepage capacity is positively correlated with rainfall, but the deeper the soil, the less the significant correlation is.