Objective To compare the safety and efficacy between flexible ureteroscope lithtripsy (FURL) and percutaneous nephrolithotomy (PCNL) in treating the renal calculus.Methods From Jan.2012 to Oct.2013,120 male and 87 female patients with renal calculus were accepted FURL (n =108)or PCNL (n=99) in our hospital.In FURL group,108 cases were classified according to the diameter of the stone,including 33 patients with the diameter of renal stone more than 20mm (range 20-39 mm,mean 29.2±5.6 mm)and 75 patients with the diameter of renal stone less than 20 mm (range 13-19 mm,mean 16.8± 1.3 mm).In PCNL group,99 cases were also classified according to the diameter of the stone,including 51 patients with the diameter of renal stone more than 20 mm (range 20-45 mm,mean 30.4±6.6 mm)and 48 patients with the diameter of renal stone less than 20 mm (range 14-19 mm,mean 17.2±1.4mm).There were no significant differences between the groups FURL and PCNL in the stone size(P＞0.05).Demographic data,operative duration,postoperative hospital stay,complication rate,and stone-free rate were recorded and compared.Results The overall stone free rate in group FURL was significantly lower 80.6％ (87/108) than that in group PCNL 91.9％ (91/99) (P＜0.05).In those patients with the diameter of stones less than 20 mm,the stone free rate was 88.0％ (66/75) in group FURL vs 93.8％ (45/48) in group PCNL (P＞0.05).The operative time was 30-65 (mean 49.5±6.9) min and 30-65 (mean 46.9±7.2) min in FURL and PCNL group,respectively (P＞0.05).In those patients with the diameter of stones more than 20 mm,the stone free rate was 63.6％ (21/33) in group FURL,which was lower than that in group PCNL 90.2％ (46/51) (P＜0.05).The operative time was 60-115 min (85.0±16.3) min and 30-95 min (68.3± 16.7) min in FURL and PCNL group,respectively (P＜0.05).The overall complication rate was significantly lower in group FURL 2.8％ (3/108) compared to group PCNL 8.1％ (8/99) (P＜0.05).Postoperative hospitalization stay were 2-6 d (3.5±1.4) d and 3-9 d (5.8±1.9) d in FURL and PCNL group,respectively (P＜0.05).Conclusions Both PCNL and FURS are efficacy and safe surgical alteration for patients with renal calculus.As to the FURS,its merits were faster recovery,less invasiveness than those in PCNL.Therefore,it can be considered as the first-line treatment for renal calculus ＜20 mm.However,for renal calculus ≥20 mm stones,FURS is still effective.