The European corn borer (Ostrinia nubilalis) is one of the most important insect pests of maize, and has a significant impact on the production of this crop. In this work, we examined the effects of different insecticides on the antioxidative defense system of O. nubilalis larvae. The experimental setup consisted of a completely randomized block design with 4 replicates. Four experimental groups were formed as follows: control (C), indoxacarb (250 mL ha-1), chlorantraniliprole (100 mL ha-1) and the chlorantraniliprole+lambda cyhalothrin (200 mL ha-1) group. Larvae from maize stems were collected 20 days after insecticide application and the whole larvae were homogenized. The activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione S-transferase (GST), and the total amount of free SH groups were assessed. Comparison of the experimental groups showed that indoxacarb significantly affected the activities of GST, GPx and the total amount of free SH groups, while chlorantraniliprole significantly affected the activities of SOD, CAT, GST and the total amount of free SH groups, while chlorantraniliprole+lambda cyhalothrin significantly affected the activities of CAT, GST and the total amount of free SH groups. The results show that exposure to insecticides considerably affects the antioxidative defense components of the European corn borer larvae, especially chlorantraniliprole (T2).