OBJECTIVE: Less fungicides could be used to biocontrol Alternaria panax and Botrytis cinerea, this experiment can offer preliminary theory for wood vinegar as a botanic fungicide. METHODS: The in vitro inhibition activities of wood vinegar on Alternaria panax and Botrytis cinerea were tested by using mycelial growth rate method and spore germination method. RESULTS: Inhibition of mycelium growth rate to Alternaria panax was 100% when the concentration of wood vinegar was no less than 3.0%, while the inhibition of mycelium growth rate and spore germination rate were 70.68% and 84.47%, respectively, at concentration of wood vinegar 2.25%. Inhibition of mycelium growth rate and spore germination rate to Botrytis cinerea were 100% when the concentration of wood vinegar was no less than 2.25%. CONCLUSION: Wood vinegar concentration of no less than 2.25% can be used as a biocontrol agent of Alternaria panax and Botrytis cinerea, it is useful for the further field trial.