Abstract: In order to explore the synergistic effects of the mixture between JS399-19 and Carbendazim on Fusarium graminearum and to find the best mixed ratio of the above two pesticides, and their mixtures (prepared by mixing 2 pesticides at the ratios of 1:1,1:2,1:3,1:4,1:5), were involved and their effects on Fusarium graminearum were tested by mycelial growth rate method. The EC50 of JS399-19, Carbendazim, and their five different ratios were 0.325, 0.367, 0.409, 0.503 and 0.531mg/L, respectively. The efficiency coefficients of the mixtures at the 5 ratios were 1.52, 1.55, 1.51, 1.29 and 1.27, respectively. The indoor biological activity of JS399-19 to Fusarium graminearum was higher than that of Carbendazim. The mixed ratios (1:1,1:2 and 1:3) of two pesticides had synergistic effects on Fusarium graminearum.