This study was conducted to investigate the effects of nickel chloride (NiCl2) exposure on oxidative stress of the abalone Haliotis discus hannai. Experimental groups were composed of one control condition and five nickel chloride exposure conditions (5.9, 8.8, 13.3, 20.0, 30.0 mg/L). Superoxide dismutase (SOD) activity was increased in the foot and hepatopancreas, but decreased in the gill. Catalase (CAT) activity was increased in all exposure groups except 20.0 mg/L and 30.0 mg/L. In the gill, CAT activity was similar to the control group for all exposure groups. In the hepatopancreas, CAT activity was increased compared with the control group. However SOD and CAT activity showed not significant differences (P > 0.05).