Taiwan is surrounded by the sea and her climate is island type, so that rainfall is often affected by the ocean air masses,
and the annual average rainfall amounts are about 2500mm. When the typhoon season is coming to the area of up-and-upper watersheds, due to the geographic weakness, steep slopeland and channel slope and fast flow that can lead to erosion, landside, mudflow and sediments deposition on the channel bed, then disaster frequentlyoccurrs.To decrease the loss of peak flow in Taiwan area, except to discuss rainfall characteriStics and peak flow mechanism in watershed, it must match the study in the mechanism of erosion,landside, mudflow and channel sediment transport, and then to carry out some treatments that can be expected to decrease the loss of disaster. Therefore, the treatment of watershed in Tat.wan area includes forest management, farmland soil and water
conservation, sabo
engineering,landside treatment, road of soil and water conservation, flow prevention engineering etc.This paper has only described the primary engineering method of soil and water conservation that was discussed the success and failure from the viewpoint and research of hydrology,hydraulics and soil mechanics. It can become the criteria of treatment for soil and water conservation in the future.