Abstract: To effectively reduce the harm of low temperature on tobacco growth, flue-cured tobacco sprayed by salicylic acid (SA) was placed at 5℃, and the effects of SA on antioxidant metabolism of flue-cured tobacco under low temperature stress were studied. The results showed that the activities of SOD (superoxide dismutase) and CAT (catalase) in tobacco leaves were increased, the relative electric conductivity was decreased, the contents of Pro (proline), chl (chlorophyll) and AsA (ascorbic acid) were raised by SA treatment,particularly at a concentration of 1.0 mmol·L^-1. It indicated that SA of proper concentration could enhance the ability of flue-cured tobacco to resist membrane lipid superoxidation and reduce the harm of low temperature.