Freezing-thawing erosion accounts for about one-third of the total soil erosion area in China. The erosion is most concentrated and strongest in the Tibetan Plateau, and becomes one of the main problems threatening the local ecological environment safety. The climate features such as low temperature and large temperature variation in the Tibetan Plateau make freezing-thawing alternate frequently and provide the suitable conditions for the type of erosion. Influenced by glaciers, snow cover and permafrost, soil erosion is driven by multi-forces including melting snow, melting ice and precipitation. As a result, the freezing-thawing erosion mechanism is quite different from other regions. In the Namco area of Tibet with strong freezing-thawing erosion, this project selects the Qugaqie catchment as the study area where mountain glaciers and permafrost coexist and water is supplied by snow and ice melt and precipitation. Through field observation of runoff and sediment load at the end of the glacier and the outlet of the catchment and monitoring of soil physical and chemical properties, soil temperature and humidity, hill slope runoff and sediment dynamics, the study will reveal the affecting mechanisms of meteorological factors, topography, vegetation, soil freezing and thawing on the melt water and rainfall erosion. Parameterization schemes of freezing-thawing soil erosion forced by melt water will be improved based on the field investigation. Using distributed, physically-based hydrological model, the hydrological and sediment processes in the catchment will be quantitatively analyzed.Through model sensitivity analysis and scenario prediction,this study will provide basis for soil erosion control and soil and water conservation planning in Tibet.