Abstract:In this study,we measured three isoflavonoids in kudzu from eight populations in south-eastern United States.The concentrations of puerarin,daidzin and daidzein in the leaves were 0.0950 mg/g,0.698 mg/g and 0.110 mg/g,respectively.The concentration of daidzin and daidzein was significantly different among populations.During the growing season,three isoflavonoids in the leaves were higher in August than in July and September.The concentrations of the three isoflavonoids in the roots were 3.664 mg/g,1.0302 mg/g and 0.3689 mg/g,respectively.There were no significant differences in the three isoflavonoids among populations.Furthermore,the concentrations of the three isoflavonoids in kudzu from US populations were higher than those of Chinese populations,as reported in previous research.This study aimed to provide a theoretic and scientific basis for making full use of kudzu leaves,determining appropriate harvest times and the development and utilization of the puerarin leaves resource.