We investigated the active oxygen scavenging activity and active compound from Humulus japonicus. The ethyl acetate and butanol fraction exhibited strong scavenging effects on hydroxyl radical. Furthermore active compound was isolated and purified using Amberlite XAD-2 column chromatography and preparative HPLC from ethyl acetate fracton, and major compound was identified as a luteolin-7-O-$eta$-D-glucoside by the MS, UV, 1H-NMR and 13C-NMR analyses. Luteolin-7-O-$eta$-D-glucoside exhibited strong scavenging effect on active oxygens such as superoxide radical, hydroxyl radical and hydrogen peroxide.