[Objective] To research the application of Pueraria peduncularis (Grall. ex Benth.) Benth in bioinsecticidal field. [Method] With the 3rd instars of Ostrinia nubilalis and Pieris rapae L. larvae as the tested insects, the insecticidal activities of n-butanol extracts, ethyl acetate extracts, petroleum ether extracts and water extracts were studied. [Result] The four P. peduncularis extracts all had certain insecticidal and antifeedant activities to the 3rd instars of O. nubilalis and P. rapae. And high concentration of extracting solution led to high activities. The insecticidal and antifeedant activities of four P. peduncularis extracts to the 3rd instars of O. nubilalis and P. rapae were in the order of n-butanol extracts > ethyl acetate extracts > petroleum ether extracts > water extracts, indicating that the components having toxicity to O. nubilalis and P. rapae were mainly soluble in highly polar n-butanol. [Conclusion] The four P. peduncularis extracts had certain insecticidal activities to the larvae of O. nubilalis and P. rapae. And n-butanol extracts showed relatively strong insecticidal activities to the two tested insects. [Method] To the 3rd instars of Ostrinia nubilalis and Pieris rapae L. larvae as the tested insects, the insecticidal activities of n-butanol extracts, ethyl ether extracts, petroleum ether extracts and water extracts were studied. [Result] The four P. peduncularis extracts all had certain insecticidal and antifeedant activities to the 3rd instars of O. nubilalis and P. rapae. And high concentration of solution solution led to high activities. The insecticidal and antifeedant activities of four P. peduncularis extracts to the 3rd instars of O. nubilalis and P. rapae were in the order of n-butanol extracts> ethyl acetate extracts> petroleum ether extracts> water extracts, indicating that the components having toxicity to O. nubilalis and P. rapae were mainly soluble in highly polar n-butanol. [Conclusion] The four P. peduncularis extracts had certain insecticidal a ctivities to the larvae of O. nubilalis and P. rapae. And n-butanolctions noted higher strong insecticidal activities to the two tested insects.