It is a threat to human health that pesticide residues in vegetables worldwide. Glutathione plays an important role in the degradation of pesticides in plant. In order to explore the role of glutathione in the regulation of pesticide metabolism in plant, tomato plants were pretreated with reduced glutathione (GSH), oxidized glutathione disulfide (GSSG), glutathione synthesis inhibitor (BSO) and H2O(CK) respectively, and glutathione related detoxification system were investigated. The results show that the increase of reduced glutathione could induce the ratio of GSH/GSSG and the activity of glutathione-related detoxification enzyme (GST) and antioxidant enzymes (GPX and GR) directly or indirectly, and contribute to the formation of non-protein thiol. Glutathione not only works as a substrate for CHT conjugation, but also induces detoxification enzyme and antioxidant enzymes associated with Chlorothalonil (CHT) metabolism and detoxification. Consequently, glutathione promoted the CHT metabolism processes and finally reduced CHT residue in plant. These observations provide evidences for the involvement of the glutathione and glutathione-dependent redox signal are critical for the induction of detoxifying response against pesticides in tomato plants. Our study provides strong evidences for understanding the mechanism of glutathione in the detoxification of CHT in vivo. (C) 2018 Friends Science Publishers.