Leaf blight is one of the main diseases of Asarum sieboldii with high incidence, chemical control is mainlyused. The inhibitory effect of Penicillium janthinellum F1-6 against Mycocentrospora acerina and its effect on defensive enzymes activity in vitro antifungi activity and pot experiment were studied in order to provide theoretical basis for biological control of Asarum sieboldii leaf blight. The results showed that the edge hyphae of the pathogenic fungi were broken and atrophied, and a large number of chlamydospores were produced. After inoculation, PPO, PAL,POD and SOD activities of healthy and infected Asarum sieboldii leaves were significantly higher than those of uninoculated healthy and infected control leaves respectively. The research results demonstrated that Penicillium janthinellum could inhibit and control of the disease by controlling the mycelial growth of the pathogen and inducing theenzyme activity of the healthy and infected plants.