Methanol extracts of 54 plant species in 32 families were tested for their antignawing activities against mice by wire-dipping method. The activity varied with plant species. Potent antignawing activity was observed in extracts from roots of Aucklandia lappa (Compositae), barks of Cinnamonum cassia (Lauraceae), fruits of Illicium verum (Magnoliaeceae), fruits of Piper nigrum (Piperaceae), rhizomes of Rheum officinale (Polygonaceae), and leaves of Pinus densiflora (Pinaceae). As naturally occurring rodent repellents, these plant-derived materials could be useful as a preventive agent against various kinds of damage caused by rodents.