Abstract: 81 Strains of Magnaporthe grisea were sampled from different areas in Liaoning Province,and their sensitivity to prochloraz was examined by the mycelium growth rate method in vitro.The results showed that the EC50 value of the most sensitive strain was 0.008 8 μg/mL and the EC50 value of the least sensitive one was 0.178 0 μg/mL,which indicated a difference of more than 19 times.According to Gaussian distribution theory of wildly sensitive strains from field,the average EC50 value 0.071 0 μg/mL±0.041 0 μg/mL was the baseline-sensitivity of Magnaporthe grisea to prochloraz in Liaoning.