Abstract:Pot experiment was conducted to study effects of Cd-Cu-Ni compound pollution on six kinds of soil enzyme activities(urease,invertase,protease,phosphatase,catalase,dehydrogenase).The results showed that six kinds of soil enzyme activities had a significant(p<0.05) or very significant(p<0.01) correlation with Cd-Cu-Ni compound pollution and the influence of Cd-Cu-Ni compound pollution on six kinds of soil enzyme activities was very different.The inhibiting effect of the three heavy metals on six kinds of soil enzymes had a toxicity order form top to bottom: Cd,Cu,Ni.Under combination of Cd-Cu-Ni,Cd and Cu mainly exhibited inhibiting effect,while Ni exhibited stimulating effect mainly.The three heavy metals all exhibited stimulating effect to some extent on phosphatase.There is highly significant negative correlation between Cd-Cu-Ni compound pollution and urease as well as dehydrogenase,so it is feasible to use soil urease or dehydrogenase activities as primary biochemical index to evaluate Cd-Cu-Ni compound pollution.