Objective：To evaluate the feasibility and efficacy of novel modular flexible ureteroscope in the treatment of upper urinary calculi. Methods: From Nov. 2013 to Jul. 2014, 36 cases of upper urinary calculi were treated with holmium laser lithotripsy through novel modular flexible ureteroscope. The clinical data including the location and diameter of the calculi, time of operation, stonefree rate, complications and hospital stay after operation were analyzed retrospectively.Results: The operation was performed successfully in 34 cases, the average time of operation was 108.5 min (70-145 min), the postoperation hospital stay was 2-5 d (average 2.3 d), and the stonefree rate was 83.33%. No serious complications occurred except postoperative fever in 2 cases and haemorrhage in 1 case. Conclusion: The novel modular flexible ureteroscope is a safe and effective medical instrumentation for treatment of upper urinary calculi.