Abstract: The semichemical ethanol of Potosia brevitarsis Lewis from the volatiles which was collected from air passed over peach fruits infested by the beetles was identified using GC-MS. The attraction of ethanol and its 8 analogous——methanol, n-propanol, i-propanol, n-butanol, i-butanol, t-butanol, n-pentanol and n-hexanol were determined in the field. The results showed that methanol, ethanol, n- and i- propanol had attractive activity to the scarab beetle, in which the activity of ethanol and i-propanol were much higher. The attraction of ethanol was as the same as its 10 times dilution, but the activity of propanol was decreased as its diluting time increased. In the blends of ethanol and i-propanol, the ratio with highest activity was 1∶ 1(V/V). And the attractive activity of all the blends became lower as the concentration decreased.