Abstrcat Soil erosion properties are analyzed to determine the impacts of soil erosion on land productivity in the Loess Plateau and the Dry-hot Valley of Jinsha River. Analysis methods used include field survey

laboratory experiments and simulation tests. Results show that soil erosion on sloping fields not only causes soil nutrient loss

but also causes degradation of soil physical properties and diminished soil infiltration capability. The consequence of theses changes brought by soil erosion is a reduction in land productivity. The impacts of similar soil erosion on the productivity of land in the Dry-hot Valley are more severe than those in the Loess Plateau

averaging 2.1 to 2.9 times more serious