The paper assessed soil environment quality of the study area by the comprehensive index method,tak-ing stream sediment samples as the research subject. The results show that the soil environment quality in the study ar-ea was generally favorable. However,the secondary pollution area and the heavy pollution area accounted for 16. 5 %of the study area's acreage. The soil was concluded to be badly polluted in local areas. The assessment provided basic geochemical data for the planning of agriculture,herding and forestry in the region.