A pot experiment was carried out to study effects of Cu stress on growth of Alternanthera philoxeroides, content of chlorophyll, biomass of the plant, and activity of four species of soil enzymes(Invertase, Catalase, Urease and Phosphatase). Results show that Cu pollution retarded growth of the plant, and reduced its average plant height, and contents of chlorophyll a and chlorophyll b. With increasing Cu content, activity of the soil enzymes decreased. The activity of the four species of soil enzymes was closely related to concentration of Cu, and hence could be used as indicator of the degree of Cu pollution in soil. In terms of sensitivity to Cu stress, the four species of soil enzymes were in the order of Invertase＞Catalase＞Urease＞Phosphatase.