Antibacterial actions against Staphylococcus aureus Terashima were examined of 64 kinds of wild plants collected in the suburbs of Mayebashi City, at the foot of Mt. Asama and the Akagi mountains, and the following 16 were found effective: Solidago Virga-aurea, Gnaphalium hypoleucum, Acanthopanax Sieboldianum, Rhus verniciflua, Hypericum erectum, Chrysanthemum morifolium var. sinense, Clerodendron trichotomum, Orixa japonica, Biota orientalis, Macleya cordata, Coriaria japonica, Sambucus Sieboldiana, Mentha arvensis var. piperascens, Petasites japonicum, Lespedeza sericea, Carpesium abrotanoides.