The effects of soil nutrients and enzyme activities under continuous cropping were investigated by collecting and analyzing soil samples from corn-seed fields in Hexi Corridor. The results showed that with the increase of continuous cropping time, the pH of both Siltigi-Orthic Anthrosols (SOA) and Sali-Aquic Vertosols (SAV) increased, organic matter decreased first and then increased, available nitrogen increased, available phosphorus increased first and then decreased and it reached the maximum in the 5a, available potassium decreased. The urease activity increased first and then decreased, it reached the maximum in the 5a for SOA and in the 3a for SAV; the sucrase activity decreased first and then increased, it reduced to the minimum in the 5a for SOA and in the 3a for SAV; the catalase activity of SOA decreased first and then increased while that of SAV increased slowly. In same continuous cropping years, the activities of urease and catalases of SOA were higher than those of SAV. There were significant positive correlation between urease activity and available phosphorus, sucrase activity and organic matter of SOA, extremely significant positive correlation between catalase activity and available nitrogent, but negative correlation between catalase activity and available phosphorus, available potassium of SAV.