Abstract: Objective:To to explore the predictive factors of the success rate of flexible ureteroscopic lithotripsy (fURL) in the treatment of single kidney stone.Methods:We retrospectively analyzed 144 patients with single kidney stone who underwent fURL in our hospital from January 2016 to December 2017.Evaluating the relationship between sex，age，body mass index (BMI)，preoperative catheterization，preoperative ESWL history，operator experience，stone location，hydronephrosis，stone diameter，stone volume，density (Hounsfield unit，HU) and the success rate of fURL.Logistics multivariate regression analysis was used to identify the independent predictors affecting the success rate of fURL.Results:There were significant differences in stone location，hydronephrosis ，experience and stone volume in univariate analysis(P<0.05).Multivariate regression analysis showed that lower calyceal stone，no hydronephrosis，less than 100 fURL experience and stone volume  were statistical significance(P<0.05).Conclusion:Stone location，hydronephrosis，operative experience and stone volume may be important predictive factors for the success rate of fURL in the treatment of single kidney stone.

Key words: flexible ureteroscopic lithotripsy, kidney stone, predictive factor