In order to obtain a comprehensive understanding about the toxicity of AHTN, the influences of AHTN on seed germination and the antioxidant enzymes in the growth of early seedlings of wheat (Triticum aestivum L.) were investigated. The results showed that AHTN had inhibition effects on the shoot elongation of wheat seedlings. And lower concentrations of AHTN (50-100 mg/kg) would promote the growth of wheat roots. There were significant (p<0.05) linear correlations between the inhibition rate of root/shoot elongation and the concentrations of AHTN. According to EC 50 of AHTN based on the inhibition of root/shoot elongation, the toxic effect of AHTN on wheat shoot was stronger than that of root. The reduction of CHL and SP content treated by 50-300 mg/kg AHTN was observed after 21day exposure. And there was good dose-response relationship between the SP content in shoot/root and the concentration of AHTN. Wheat has a stronger capacity to endure the oxidative stress of AHTN. However, the endurance is limited. With the prolongation of stress time and the increasing of pollutant concentration, the capacity of withstand the menace would fade away. After the 21-day exposure, the activity of SOD and POD obviously decreased and the antioxidative system of wheat was destroyed.