Effects of alternative continuous cropping of poplar cuhivars on soil biochemical properties along Shu River in Ju county, Shandong, were studied. Results showed that, content of available N, P, K and trace element of Cu and Zn were same between alternative continuous cropping and unahernative continuous cropping, but soil organic matter and trace element Mn were different signifcantly. Soil organic matter in alternative continuous cropping treatment was higher, but trace element Mn was lower than unahernative continuous cropping treatment. Compared with unalternative continuous cropping, soil enzyme activity of urease and peroxidase in alternative continuous cropping treatments increased significantly by 184.7 % and 40. 5 %, but catalase decreased significantly by 11.8%. And polyphenol oxidase activity increased by 32.3% with no significant difference between treatments and CK. With soil depth increased, urease activity decreased steadily, and the other three enzymes had no variety trend. The quantity of soil fungi, bacteria, actinomyces in alternative continuous cropping treatments was higher than that of CK, signifcantly.