Abstract: Inhibition of fungicide Yintai (The effect component is 4 butanoyl phenol) on the pathogen of Rhizoctonia cerealis and its disease control effect were tested respectively by means of growing rate method and field experiment. The results showed that 20% Yintai EC played a stronger inhibiting effect on Rhizoctonia cerealis when the concentration of Yintai EC increased from 0 to 100 μg/mL. Its EC50 and EC95 were 36.11 μg/L and 97.66 μg/L. Its EC95 was significantly lower than the EC 95 value of Jinggangmycin (327.64 μg/L). The field trial indicated that the control effect of 20% Yintai EC on the sharp eyespot of wheat were 85.8%, 89.3% and 92.3% when it was used at the concentration of 200, 400 and 800 mg/L, respectively. This control effect was as good as the treatment of 70% thiophanate methyl WP(400 mg/L).