Abstract: Objective:To evaluate the clinical effects of the electronic fexible ureteroscopy combined with holmium laser lithotripsy(FURL) in the tretment of kidney and upper ureteral calculi.Methods:The clinical data of 42 kidney and upper ureteral calculi patients treated with FURL were retrospectively analyzed.The operation time,stone-free rate(SFR),and complications were evaluated.Results:A total of 42 patients were treated with FURL.The mean operative duration and first stage SFR in 27 cases with the diameter of calculi ≤2 cm were (73.9±21.2)min and 100%,respectively.The mean operative duration and first stage SFR in 11 cases with the diameter of calculi >2 cm and ≤3 cm were (94.5±29.1)min and 81.8%,respectively.The mean operative duration and first stage SFR in 4 cases with the diameter of calculi >3 cm were (120±36.7)min and 25.0%,respectively.The difference of the first stage SFR between the patients with the diameter of calculi ≤2 cm,and >2 cm and ≤3 cm was not statistically significant(P >0.05),while the first stage SFRs of whose were higher than that in patients with the diameter of calculi >3 cm(P<0.01 and P<0.05).The number of fever patients in positive urine leukocyte group were higher than that in negative urine leukocyte group.The fever in 8 patients and no other serious complications were found.Conclusions:The treatment of kidney and upper ureteral calculi with the diameter ≤2 cm with FURL is minimally invasive,safe and effective.