The objectives of this study were to investigate the radical-scavenging activity of Ligularia fischeri on oxidative damage by the radical 1,1-diphenyl-2-picrylhydrazyl (DPPH) and to rapidly identify the active components using the bioassay-linked fractionation method. The MeOH extract and fractions of CH(2)Cl(2), BuOH, and H(2)O from L. fischeri showed DPPH radical-scavenging effects in a dose-dependent manner (p < 0.01). In particular, the BuOH fraction had the most effective (p < 0.05) antioxidative capacity. The active constituents from the BuOH fraction of L. fischeri were rapidly isolated by bioassay-linked HPLC method and identified as hyperoside and 2''-acetylhyperoside with potent antioxidant effects against the DPPH radical, with IC(50) values of 1.31 and 7.09 microg/mL, respectively. They have not been reported from L. fischeri yet.