This paper,aiming at detecting the difference of soil losses under different vegetation types,analyzed the dynamic processes of soil and water loss under forest with different tree species using 9years'dataof 6runoff plots observated in 1995-1997from Lanxi comprehensive test station of soil and water conservation in Zhejiang Province.The results were as following:(1)In the first 2years after tree planting,soil andwater loss were very serious.Soil and water loss were above 90percent of all 9years'except tea garden andpine tree,but the soil loss decreased with tree growth due to improvement of soil and water conservation capabilities of these forest.Soil erosion and sediment yield were almost not detected in some forests;(2)Soilerosion intensity in the first 2years follows an order:china fir forest>dense citrus forest>sparse citrus forest>bamboo forest>mixed forest.The coniferous and broad-leaved mixed forest is the most effective in reducing the soil and water loss;(3)Soil and water loss did not vary with the time,and the significant interannual fluctuations was detected in tea orchard due to the interference of artificial fertilization and pickingtea.Some conclusions could be drawn that in the cultivation processes of soil and water conservation forest,the first 2years was an important period to the control of soil and water conservation.Strengthen the production management of tea garden fertilization and picking tea were specially the key measures to reducingsoil and water losses.