Abstract: In this study,the RUSLE model and the RS and GIS means were used to estimate the soil erosion in 10 years from 2004 to 2014 in Tianzhu County and Hezuo City in Gansu Province,where the household contract system and allied household contract system were separately implemented.The purposes of this study were to compare the grassland management regime in alpine meadow,improve the rangeland management system,and analyze the correlations between the soil erosion and the annual precipitation,farmer population,livestock number and animal husbandry production value.The reasons causing the difference of soil erosion modulus of grassland in two counties were analyzed by exclusion method.The result showed that: ① Slight soil erosion occurred in both Tianzhu County and Hezuo City. ② The average annual modulus of soil erosion in Tianzhu was 7.21 (t·a·km^-2) and higher than that in Hezuo City.The increase rate of soil erosion in Tianzhu County was 4 times of that in Hezuo City.The increase of soil erosion modulus of all grassland types in Tianzhu County was higher than that in Hezuo City. ③ There was a significant positive correlation between annual precipitation and soil erosion (R=0.737,P<0.05) in Tianzhu County.In Hezuo,there was a significant negative correlation between farmer population and average rangeland erosion modulus (R=-0.829,P<0.05). ④ There was no correlation between the difference of grassland erosion modulus and the annual precipitation difference in both Tianzhu County and Hezuo City (P>0.05).The livestock overload rate in Hezuo City was higher than that in Tianzhu County.This study suggests that grassland management model is the main reason causing grassland degeneration and soil erosion,and the allied household management regime is superior to the individual household management regime in controlling soil and water erosion.

Key words: soil erosion, rangeland management model, soil and water loss, alpine meadow, Gansu