Abstract: Laboratory studies were done to determine the repellency effects of essential oil derived from three species of Euealyptus leaf against adults Apriona germari, Psacothea hislaris, and Monochamus alternatus. Results indicated that essential oil of Eucallyptus citriodora and E. globulus had a significant repellency effect. Among three species of essential oil, the essential oil of E.citriodora was the most effective. When host plants were treated with a concentration of 10％, the essential oil of E.citriodora， the repellent time of A.germari, P.hislaris, and W.alternatus was 9 d, 12 d, and 4 d, respectively with treatment of adults with a concentration of 0．625％， the repellent time was 5 d, 11 d, and 1 d, respectively. No significant Prepellency effects had been found when adults were treated with essential oil of E.exserta.