Hydroponic experiments were conducted to investigate the effects of exogenous GSH on plant growth and root activity,as well as electrolytic leakage rate,the contents of lipid peroxidation (MDA),proline (Pro) and soluble sugar and the activities of superoxide dismutase(SOD),peroxidase(POD) and catalase(CAT) in leaves of tomato seedlings under NaCl stress.The result shows that:1)NaCl stress significantly inhibited the growth and root activity of tomato seedlings and decreased the activities of SOD,POD and CAT,and increased electrolyte leakage rate and the contents of MDA,proline (Pro) and soluble sugar in leaves of tomato seedlings.2)The application of exogenous GSH induced the upregulation of POD,SOD and CAT activities,decreased the electrolyte leakage rate and MDA contents,and returned the contents of proline and soluble sugar to control level in leaves of NaClstressed tomato seedlings.3)The application of exogenous BSO decreased root activity and POD,SOD and CAT activities,and increased proline contents in leaves of tomato seedlings under NaCl stress.4)Spraying GSH increased the root activity and SOD,POD and CAT activities,decreased the contents of MDA and Pro in combined stressed (NaCl and BSO) plants.These results suggested that GSH alleviated saltinduced growth inhabitation and enhanced salttolerance by promoting the osmotic adjustment capacity and the defense ability of antioxidant enzyme system to decrease membrane lipid peroxidation and protect the integrity of membrane structure in tomato seedlings under NaCl stress.