Abstract: To confirm the sensitivity of Valsa mali to ethylicin, the sensitivity baseline was established by measuring the mycelial growth of 108 isolates collected from seven provinces of China in seven different years on the media supplemented with series of ethylicin concentrations. The results indicated that 50% effective concentration （EC₅₀） values ranged from 3.6023 to 55.7283 μg/mL. Sensitivity frequency distribution showed a continuous single peak curve, presenting a normal distribution. No resistant strain to ethylicin was found in the tested isolates, and the average EC₅₀ value （17.242 1±0.929 2） μg/mL could be the sensitivity baseline of V. mali to ethylicin based on analyzed results by K-S method. The isolates collected from different regions showed different sensitivities. The sensitivity of V. mali from Henan Province was the highest, while that from Shanxi Province was the lowest. The sensitivity of tested strains in different years did not show an obvious pattern of change with the years, suggesting that V. mali is still in a sensitive population stage to ethylicin. The results provide important guidance for the scientific application of ethylicin.