Abstract: To investigate the physiological response characteristics of ginger under heat stress，a sandy-cultured experiment was conducted to study the effects of high temperature on active oxygen metabolism of ginger leaves and the mitigation effect of SNP（sodium nitroprusside，a NO donor）application in ginger leaves under heat stress. Such as pigments content，reactive oxygen species level，enzymatic and non-enzymatic antioxidant systems were considered in this study. A significant decrease of pigments content as well as accumulation of ，H₂O₂ and MDA were observed in heat-stressed ginger leaves. Additionally，SOD，POD and CAT activities were enhanced at the early stage of heat stress，which were then sharply inhibited with the stress time prolonging and blocked AsA–GSH cycle. Compared with the control treatment，application of 0.1 mmol · L^-1 SNP significantly enhanced activities of antioxidant enzymes as well as palingenesis of AsA–GSH cycle that significantly decreased levels of reactive oxygen species and membrane lipid peroxidation. Furthermore，application of SNP conferred ginger plants heat stress tolerance by pigment contents analysis.

Key words: ginger, Zingiber officinale, heat stress, nitric oxide, reactive oxygen metabolism