Abstract: Taking Isatis indigotica as the test material,the effects of wood vinegar spray on the growth and physiology of I satis indigotica seedlings under water soaking and 15% PEG 6000 soaking were studied by means of greenhouse pot pot method,in order to provide reference for the application of wood vinegar solution to the green and ecological planting of Isatis indigotica and other medicinal plants.The results showed that,the suitable concentration of wood vinegar sprayed on the leaf surface significantly promoted the growth of Isatis indigotica seedlings,alleviated the inhibition effect of PEG 6000 stress on the growth of seedlings,and increased chlorophyll content,photosynthetic rate,transpiration rate,stomatal conductivity and water utilization rate.The content of malondialdehyde（MDA） and the activities of superoxide dismutase（SOD）,peroxidase（POD） and catalase（CAT）were decreased with 400 times liquid.