On the basis of the data of the firsthand observations in the Hemingguan Watershed, a study was made on benefits of comprehensive control in reduction of water and sediment. Results show that rainfall, runoff and sediment are concentrated in the high-water season (May to October), the sequence of annual rainfall and runofff has little declining tendency while the sequence of annual sediment transportat ion declines evidently, which indicat es the turning-better tendency of water and sediment in the watershed after comprehensive control. Among the conservation measures taken, water conservancy practices and conservation engineering play a leading role in reducing water and sediment. The benefit of afforestation and grass-planting is remarkable but noticeable in hysteresis.