Abstract: Based on RS and GIS technology, the RUSLE model to evaluate the soil erosion in the source of the three rivers region in 2010 and 2015 was used. At the same time, the continuous substitution method was introduced to explore the influencing factors of soil erosion change,and the multi-factor cross-effect problem was solved. The results showed that the source of the three rivers region presented a large spatial distribution of erosion in the central and eastern parts and less erosion in the east and west. With the increase of elevation and slope length, the soil erosion modulus increased, and the slope length factor increased larger than the elevation. The slope length factor was more sensitive. Overall soil erosion modulus was reduced in 2010—2015, modulus was reduced in the central and western regions, and modulus was increased in the eastern region. The continuous substitution method was better quantitatively described the amount of soil erosion caused by the rainfall and vegetation factors and its spatial distribution. The impact of rainfall on the whole area was large and the degree was low, and the range of vegetation impact was relatively concentrated and deep.

Key words: RUSLE, soil erosion, the continuous substitution method, the source of the three rivers region