In Lanzhou-Baiyin area, the composite effects of various natural and geological actions and human activities have resulted in obvious nonequilibrium in the distribution of nutritional elements as well as toxic and harmful components in the surface layer soils. A quality assessment of agricultural soil in this area was conducted based on the content distribution of elements determined by soil-dominant multi-media geochemical measurement and the investigation of current situation of soil pollution together with the abundance of beneficial elements. It is concluded that the ecological risk and the discrete intensity of enrichment pollution of heavy-metal elements Cr and Ni are relatively weak, while high discretization of Cd, Hg, Pb ,Zn, Cu and As exists. The agricultural soil has been divided into three levels, i.e., excellent level (first level), general level (second level) and bad level (third level), and some principles of fertility and measures for remedy have been brought forward accordingly.