Abstract: In order to select effective chemicals to control Phyllosticta commonsii, indoor toxicity of twelve fungicides on Phyllosticta commonsii, and their relative inhibition rates at 10 mg/L against Phyllosticta commonsii were tested by the hypha growth rate in lab and toxicity measurement with five different concentrations. The results showed that, at 10 mg/L, 70% chlorothalonil WP had the strongest relative inhibition rate against Phyllosticta commonsii, with the relative inhibition rate of (65.19±2.80)%; then was the relative inhibition rate of the 80% mancozeb, which was (64.81±4.49)%, the relative inhibitory rate of 32% YBJ was the lowest, which was (25.56+4.01)%. The results indicated that in laboratory, eight kinds of fungicide of the test concentration had a certain inhibition effect on the growth of Phyllosticta commonsii. Muldewcarbendazim (50%) showed the best effect on the Phyllosticta commonsii, its EC50 value was only 2.6268 mg/L, the following one was chlorothalonil WP (70%), its EC50 value was 2.9781 mg/L. In addition carbendazim and hymexazol also had effective inhibition. The study provided the basis for controlling Phyllosticta commonsii in field.