Abstract: Effects of copper on lethal rate and Cu enrichment of Bellamya aeruginosa and CAT and SOD activities in the hepatopancreas of Bellamya aeruginosa under Cu stress were studied. Bellamya aeruginosa was collected from a river in Chashan of Ouhai,Wenzhou City,Zhejiang Province.Results show that Bellamya aeruginosa was quite capable of tolerating low concentrations of Cu²⁺（1.0 and 2.0 mg·L^-1）,but showed a relatively high hethal rate when ρ（Cu²⁺）was in the range from 4.0 to 8.0 mg·L^-1.When ρ（Cu²⁺）was 0.2-0.8 mg·L^-1,Bellamya aeruginosa enhanced its Cu enrichment with its exposure to the toxicant getting longer and the toxicant higher in dosage.However,when ρ（Cu²⁺）reached 1.6 mg·L^-1,its Cu enrichment declined with the duration of its exposure.Cu stress significantly affected CAT and SOD activities in the hepatopancreas of Bellamya aeruginosa .