Abstract: The objective of this study was to determine the effects of CO₂ laser(wavelength 10600 nm,power density 20.1 mW/mm²) on glutathione dependent antioxidative system in wheat seedling under drought stress.Germinating seeds were exposed to CO₂ laser radiation for 0 min,1 min,3 min and 5 min,respectively,then they were treated with 10%(W/V) PEG6000 solution for 8 days.When the seedlings were 12-day-old,changes in the concentration of oxidized glutathione(GSSG),reduced glutathione(GSH),ascorbate(AsA) and the activities of glutathione reductase(GR),glutathione-S-transferase(GST),ascorbate peroxidase(APX) were measured to determine the effects of laser.The results showed that suitable laser treatment of seeds improved drought tolerance in wheat seedlings by decreasing the concentration of GSSG and increasing the activities of APX,GR,GST,AsA and GSH concentration.The results suggested that those changes in glutathione dependent antioxidative system were responsible for protection wheat against drought induced oxidative damage.