Abstract: Toxicity of natamycin on the mycelial growth,conidial germination and sclerotium germination of Botrytis cinerea was tested,using carbendazim as control,through growth rate method,hanging drop slide method and pickling method,respectively.The effects of the two fungicides on the sporulation and sclerotigenic of Botrytis cinerea were also studied.The results indicated that toxicity of natamycin and carbendazim to Botrytis cinerea at different growth stages enhanced as the temperature decreased.Conidia was the most sensitive to the two fungicides.Temperature showed the most significant effect on mycelial growth.The activity of carbendazim was higher than that of natamycin.The two fungicides have no effect on the time of sporulation and sclerotigenic of Botrytis cinerea,but carbendazim can stimulate the producing of sporulation and sclerotigenic significantly.