Abstract: We investigated the activities of superoxide dismutase (SOD) and catalase (CAT), total antioxidant capacity (TAC) and content of malondialdehyde (MDA) in the adductor, gill and mantle of pearl oyster (Pinctada fucata) after the pearl-nucleus-inserting surgery (without nucleus and mantle piece), so as to study the effect of the surgery damage on anti-oxidation and immunity.The results show that the SOD, CAT activities and TAC in these three tissues experienced an increase-decrease-increase fluctuation after the surgery, and most of them reached the lowest values at the 3^rd hour and the highest values at the 12^th hour post-surgery.In contrast, the overall trend of MDA content was increasing during the experiment.Correlation analysis shows that CAT activity and TAC had significant negative correlation with MDA.Besides, significant difference was also detected in SOD, CAT activities and TAC among different tissues (P < 0.01), as well as at different sampling time (P < 0.01).The study suggests that the surgery damage may lead to fluctuation of anti-oxidation and immunity of P.fucata, and oxidant damage is closely related with the antioxidant status.