To determine the potential effects of fullerenes (C60) on aquatic organism, larval Carassius auratus was exposed to low level C60 (0.04-1.0 mg x L(-1)) for 32 days. Then the oxidative damages in brain, liver and gill tissue of larval Carassius auratus were measured. The results showed that: compared to the control, the reduced glutathione (GSH) contents in all different tissues decreased significantly (p < 0.05), and the most serious inhibition of GSH with a 14.3% inhibition rate was found in the gill tissue of larval crucian exposed to 1 mg x L(-1) C60 aqueous suspension; whereas the superoxide dismutase (SOD) and catalase (CAT) activities in liver tissue, Na+ -K+ -ATPase activities in gill tissue were stimulated significantly (p < 0.05), and the maximal activity of them were 121.34% (exposed to 0.04 mg x L(-1) C60 aqueous suspension), 114.80% (exposed to 0.04 mg x L(-1) C60 aqueous suspension) and 348.59% (exposed to 0.20 mg x L(-1) C60 aqueous suspension) respectively than that of control. The experiment results indicated that oxidative damages induced by long-term exposure might play a role in the bio-toxicity of C60 to larval crucian.