Abstract:Soil enzymes in Shanghai were tested in the typical green-belts soil of iron-steel factories, ship-building, chemical-reagent factories, traffic areas and residential quarter. Influences of catalase, alkaline phosphatase, urease and dehydrogenase were discussed on different heavy metals, physical and chemical properties. The results showed that the enzyme activities were affected by heavy metals, physical and chemical properties of soil; density, pH, CEC and Cr influenced mainly catalase activity. Organic matter, hydrolysis of N, Pb and Zn influenced mainly alkaline phosphatase. CEC, pH, density and hydrolysis of N influenced mainly dehydrogenase. Hydrolysis of N, CEC, pH and density influenced mainly urease. Catalase, alkaline phosphatase, urease and dehydrogenase activity were different in the different land-use types. Catalase activity was higher, but the alkaline phosphatase activity was lower in the survey areas; Urease activity was higher in reagent Factory and traffic areas; Dehydrogenase activity was higher in traffic areas and reagent Factory.