This study the effects of Cu exposure on biochemical factors in the hemolymph and hepatopancreas of the abalone $Haliotis$ $discus$ $hannai$. Abalone were exposed to 0, 5, 10, 20 and 40 ${mu}g/L$ Cu for 4 weeks. The calcium concentrations in hemolymph were decreased significantly on exposure to 20 and 40 ${mu}g/L$ Cu after 2 weeks. The aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) activities in abalone hemolymph were markedly elevated after exposure to 40 ${mu}g/L$ Cu for 4 weeks. The hepatopancreas superoxide dismutase (SOD) and catalase (CAT) activities were also significantly increased by exposure to 20 ${mu}g/L$ Cu for 4 weeks. These biochemical factors may represent a convenient method of monitoring heavy metal pollution in coastal areas. From these results, we conclude that a high copper concentration (40 ${mu}g/L$) in water may curtail hemolymph homeostasis and anti-oxidative reactions in abalone.