In this study,the toxic mechanism of Patinopecten yessoensis responding to copper exposure was investigated through analyzing the effect of copper on bioaccumulation,activity of antioxidant enzymes and lipid metabolism in the gill or hepatopancreas.The results showed that the maximum accumulation of copper(0.025,0.05 and 0.10 mg/L)in gill occurred at 14 d(347.55 μg/g),6 d(340.72 μg/g)and 6 d(302.30 μg/g)respectively.With the time extension,accumulation of copper has a curvilinear relationship except 0.10 mg/L group.However,concentration of copper in 0.10 mg/L group of hepatopancreas presented liner changes with exposure time and the peak occurred at 14 d(60.88 μg/g).The corresponding changes in 0.025 and 0.05 mg/L were curvilinear and even decreased.Also,SOD,CAT and GPx activities were significantly suppressed in gill following copper exposure.However,in hepatopancreas,0.025 mg/L and 0.05 mg/L groups could induce the expression of antioxidant enzymes in 24 h except GPx in 0.05 mg/L group.The activities of all the three enzymes in 0.10 mg/L group were suppressed during all the experiment.Furthermore,the key regulation factors related to lipid metabolism including PPARs-γ2,6PGD,G6PD,FAS,LDH were found significantly up-regulated in the hepatopancreas,except ACC,CPT1 by using next generation sequencing technology.These results suggest that gill was the main accumulation tissue of copper in P.yessoensis,while the hepatopancreas was more sensitive to higher concentration.Also,the toxicity of copper was more serious than cadmium for P.yessoensis by damaging the activity of antioxidant enzymes in both tissues and inducing the accumulation of lipid in hepatopancreas.