Abstract: Taking 3 types of mixed plantations soil in Hunan as the research object and 2 types of pure plantations of Zelkova serrata and Cunninghamia lanceolata as the control. The activities of soil enzymes such as catalase, peroxidase, protease and urease were analyzed to evaluate the effects of different mixed modes on plantationsland. The results showed that most of the soil enzyme activities had significant differences under different mixed plantations mode, especially the surface layer was more obvious. In all mixed plantations mode, the soil enzyme activities of mixed plantations were significantly higher than pure Cunninghamia lanceolata plantations. The rule of soil enzyme activities in difference soil layers was the surface > middle > lower. In the hill country area, the mixed plantations (Cunninghamia lanceolata:Zelkova serrata:Choerospondias axillaris=6:2:2) had better effect of improving soil enzyme activity.