Abstract: In order to find a solution to low temperature damage during tobacco seedling culturing in south China,aerobic fermentation bedding was experimented with local conventional seedling culturing method as the control,the water temperature in nutrition pool,growing period of tobacco seedling and vigor of grown seedlings were determined.The results showed that laying 10 kg bagasse and 2 kg rice straw under the seedbed could increase water temperature by 3℃,reduce seedling growing period by 17 d,and the grown seedlings had stronger stems,more leaves and well developed and vigorous root systems.The total absorption area and active absorption area of root system were obviously larger than that of the control.In addition,the activities of nitrate reductase and superoxide dismutase,contents of chlorophyll and soluble protein were higher,while the contents of free praline and malondialdehyde were much lower than the control.