In order to verify the efficacy of Lespedeza cuneata G. Don which have been used as a folk traditional herb medicine from ancient times, the test of antioxidant activity and the analysis of constituents were carried out. Methanol extracts from L. cuneata G. Don showed a radical scavenging activity corresponding to that of (+)-catechin as positive control at 250 ${mu}g$/mL (ca 90% inhibition), and inhibited more than 30% of DPPH radical at low concentration of 10${mu}g$/mL. In the present study, as a fundamental study for the specification of antioxidant components from L. cuneata G. Don, the analysis for constituents for L. cuneata with HPLC was preformed although there was no results to identify functional flavonoids such as quercetin.