Abstract: To evaluate the effects of dietary aflatoxin B₁ (AFB₁) on growth performance, antioxidant capacity, histological changes and accumulation in juvenile marbled eel (Anguilla marmorata), triplicate groups of marbled eel with initial body weight of (6.41±0.10) g were fed with four diets containing 0, 10, 100 and 1000 μg/kg AFB₁ for a 56-day trial. No unusual behavior or external changes were observed in fish fed diets containing AFB₁. Significant lower survival rate, Final Body Weight (FBW), Feeding Rate (FR), Specific Growth Rate (SGR) and Feed Efficiency (FE) were observed in 1000 μg/kg AFB₁ group, while no significant differences were found among other groups. There were no significant differences in activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione S-transferase (GST), and malondialdehyde (MDA) in liver between the control and 10 μg/kg AFB₁ diet group. AFB₁ above 100 μg/kg significantly impacted activities of liver SOD, GSH-Px and GST. No significant histological lesions in liver were identified under the microscope in the control and 10 μg/kg AFB₁ diet groups. Severe vacuolar degeneration of hepatocytes was found in 1000 μg/kg AFB₁ group. AFB₁ accumulation in liver and muscle significantly increased with increased dietary AFB₁ levels, with 17.75 and 5.98 μg/kg in 1000 μg/kg AFB₁ group, respectively, which are above the safety limitation of 5 μg/kg as proposed by FDA. These results indicate that 10 μg/kg AFB₁ is the safe level in juvenile marbled eel diet.