Abstract: Objective The experiment was conducted to investigate the effects of forchlorfenuron on yield and quality of kudzu root to provide reference for high-yield,high-quality cultivation and medical resource development of kudzu root.Method In this study,in order to evaluate the effects of forchlorfenuron in different concentrations on the yield and quality of kudzu,1,5,25 and 50 mg/L forchlorfenuron were sprayed on Guige 1 during the expansion of root tuber,with the treatment of spraying clear water as CK.Content of chlorophyll were measured after 30 and 60 d,and growth traits,quality traits and main medicinal ingredients were measured six months later.ResultThe results showed that,in comparison with CK,forchlorfenuron significantly improved the contents of chlorophyll,promoted the length and width of root tuber and dry matter content.But its effects on the fresh weight per plant,contents of starch,soluble sugar and medicinal ingredients varied.The diameter of tuberous root,average fresh weight per plant,dry matter content,the contents of starch and soluble sugar were the highest when treated by 1 mg/L forchlorfenuron,all significantly higher than those of CK (P<0.05,the same below).The contents of total flavinoids and puerarin were the highest when treated by 5 mg/L forchlorfenuron,all significantly higher than those in CK,and the diameter of root tuber,dry weight and contents of soluble sugar and cellulose were relatively higher,When treated by 25-50 mg/L,the content of cellulose was significantly improved than that of CK,but other indicators of quality and medicinal ingredients were lower than those in CK or not significantly different from those in CK.Conclusion Spraying forchlorfenuron in the period of kudzu root expansion influences growth,yield,quality and medicinal ingredients of Guige 1 to various extents.Spraying 1-5 mg/L forchlorfenuron has the optimal effects on yield and quality improvement of kudzu root.