The antioxidant activities of the ethanol extract of Arctium lappa were assessed by measuring the 1, 1-diphenyl-2-picryl- hydrazyl(DPPH) radical scavenging effect, inhibition of Fe2+-induced lipid peroxidation, inhibition of malondialdehyde(MDA)- bovine serum albumin(BSA) conjugation reaction and antimutagenic capacities using the Ames test. The DPPH radical scavenging activity and inhibition of Fe2+-induced lipid peroxidation of the Arctium lappa ethanol extract significantly increased in a dose-dependent manner. In the radical scavenging assay using DPPH, the IC50 of the Arctium lappa extract was 296 ㎍/assay(1.29 ㎎ of dry sample). In addition, the IC50 in the inhibition of Fe2+-induced lipid peroxidation was 1, 759 ㎍/assay(7.65 ㎎ of dry sample). This extract also significantly inhibited the MDA-BSA conjugation reaction with an IC50 of 57.58 ㎎/assay(250 ㎎ of dry sample). However, no inhibitory effects against the direct and indirect mutagenicities in Salmonella Typhimurium TA98 and TA100 were observed. Based on these results, the ethanol extract of Arctium lappa was shown to display considerable antioxidative activities.