Objective：To compare the efficiency and safety of two kinds of stone baskets using in flexible ureteroscopy. Methods：Totally 75 patients with renal stones who underwent flexible ureteroscopy were randomly divided into two groups，and were treated by the same team of surgeons. For patients in group A，the stone fragment was catched out with Escape nitinol stone retrieval basket（Boston Scientific Corporation，USA，Catalog NO. M0063902010），and for patients in group B，the stone fragment was catched out with Ncircle nitinol tipless stone extractor（Cook Incorporated，USA，Catalog NO. NTSE-022115-UDH）. The clinical data such as basketing efficiency，operation time，stone free rate and complications were compared between two groups. Results：The average bas－keting time was 27 minutes in patients of group A，and 35 minutes in patients of group B. The average best basketing frequency in one minute was 7.70 in patients of group A，and 3.87 in patients of group B. The stone free rate one month after operation was 89.19% in patients of group A，and 68.42% in patients of group B. All these three clinical data of group A was superior to that of group B，and the difference had statistical meaning. The average operation time was 68 minutes in patients of group A，and 71 min－utes in patients of group B. The complication rate was 5.41% in patients of group A，and 5.26% in patients of group B. There was no statistical difference in these two clinical data. No damage occurred no matter in the collecting system of patients or in the ureter－scopes due to stone baskets. Conclusion：Both stone baskets are safe for flexible ureteroscopy. A suitable stone basket would improve the basketing efficiency and stone free rate of flexible ureteroscopy.