Abstract: We studied the gender differences of the neurotoxicity and oxidative damage effects of triazophos on Perna viridis that has function of environmental indicator for the first time. The changes of acetylcholinesterase (AchE) and several antioxidant indices in gill tissues of male and female were determined after 15 d of chronic exposure to 35 μg·L⁻¹ (1/100 96 h LC₅₀). The results show that there was no significant change in the AchE activity in female's gill tissue after being treated with triazophos for 15 d, while the AchE activity in male was significantly inhibited. The activities of superoxide dismutase (SOD) and catalase (CAT) in gill tissues of both male and female were significantly inhibited, and the malondialdehyde (MDA) content was significantly increased. The activity of glutathione S-transferase (GST) and the content of reduced glutathione (GSH) showed significant gender differences. Only the GST activity and GSH content in male had significant changes. In conclusion, triazophos shows obvious neurotoxicity and oxidative damage effects on gill tissue of P. viridis, and the male was more sensitive to triazophos exposure.