Successive extraction method was adopted to study the relationship between characteristics of chemical forms of cadmium and lead and four soil enzymatic activities(Calatase,Urease,Invertase,Alkalin phosphatase) in alluvial meadow soil and meadow cinnamon soil by field sampling.The result showed that the most contributions to inhibiting effect of soil enzymatic activities,especially to Urease activities in lowly polluted soils,were the exchangeable Cd and Pb,the next were the Fe-Mn oxide Cd and Pb.When the Urease activities was decreased by 10% in meadow cinnamon soil,the concentration of exchangeable Cd, Pb were 0.09 mg kg^-1,0.12 mg kg^-1 respectively and in alluvial meadow soil,the concentration of the exchangeable Pb was 0.92 mg kg^-1.In calcareous soils,it was feasible to use the exchangeable Cd,Pb and Urease activities as primary biochemical index to evaluate Cd,Pb polluted soils.