Abstract: Heat-shock pretreatment at 42℃ for 4 h and recovery at 26 .5℃ for 4 hgreatly improved greatly survival percentage of maize seedlings under high temperature stress . Heat-shock pretreatment and recovery at 26. 5℃ for 4 h significantly enhanced the activities of antioxidant enzymes CAT, SOD, GR and APX and the levels of antioxidants ASA and GSH in maize seedlings . The seedlings with heat-shock retained higher activities of antioxidant enzymes and higher levels of antioxidants than that without heat-shock during heat stress and recovery , indicating that the increase of activities of antioxidant
enzymes and levels of antioxidants is the physiological basis for the formation of heat tolerance induced by heat-shock in maize seedlings .

Key words: Maize ( Zea mays) seedlings