[Objective] The paper was to study the insecticidal effect of water extract of oleander (Nerium indicum) against the larvae of Enmonodia vespertilio Fabriciu. [Method] Through feeding experiment on the larvae of E. vespertilio, the insecticidal effect of water extract of oleander against the larvae was studied. [Result] The 1/20-1/200 times water extract of dry leaf weight of oleander had better insecticidal effect against the larvae of E. vespertilio, and the feeding mortality rate reached 100%. [Conclusion] The paper provided reference for development of new botanical pesticides with high efficiency, environmental protection and low carbon. [Objective] The paper was to study the insecticidal effect of water extract of oleander (Nerium indicum) against the larvae of Enmonodia vespertilio Fabriciu. [Method] Through feeding experiment on the larvae of E. vespertilio, the insecticidal effect of water extract of oleander [Result] The 1 / 20-1 / 200 times water extract of dry leaf weight of oleander had better insecticidal effect against the larvae of E. vespertilio, and the feeding mortality rate reached 100%. [Conclusion] The 1 / 20-1 / 200 times water extract of dry leaf weight of oleander had better insecticidal effect against the larvae of E. vespertilio, and the feeding mortality rate reached 100% The paper provided reference for development of new botanical pesticides with high efficiency, environmental protection and low carbon.