Objective：To evaluate the safety and effectiveness of treating residual stones after percutaneous nephrolithotomy （PCNL） with flexible fiberscope（choledochofiberscope） in outpatient department. Methods：The patients with residual stones after PCNL were treated by flexible fiberscopy to deal with residual stones. The removal of the residual stones and patients’tolerance were observed. Results：There were 22 cases in 52 cases（42.3%） whose residual stones were cleared completely in one time. The residual stones were cleared completely in 38 cases（73.1%）. Conclusion：Application of flexible fiberscope（choledochofiberscope） in treating residual stones in outpatient department after PCNL is safe，economical and effective.