Abstract: This paper researched on the soils in Daqing city for example.Based on the field survey datas and applying single factor index and the potential ecological risk index introduced by a scholar in Sweden. The results show that steep natural pond area is contaminated slightly, and pastoral area is contaminated lightly; and that industrial district, living area, oil extraction area, the nature reserved all suffer medium contamination. Cd is the main contribution. It has already bad effects on ecological environment of the city.