Abstract: Objective: To compare the safety and efficacy between flexible ureteroscopy and Microperc in the treatment of kidney stones less than 2 cm in infants. Method: The clinical data of infants with flexible ureteroscopy and Microperc operation in our hospital from October 2016 to October 2017 were analyzed retrospectively, and two groups were divided according to the surgical methods. There were 38 cases in flexible ureteroscopy group, 25 males and 13 females. The average age was(19.6±9.9) months, the maximum diameter of the stone was(13.7±4.5) mm, and the number of stones was(1.29±0.57). There were 29 cases in group Microperc, 19 males and 10 females. The average age was(20.7±10.6) months, the maximum diameter of the stone was(13.9±4.5) mm, and the number of stones was(1.31±0.54).All patients were retained 4.7 Fr double J tube 2 weeks before operation. The flexible ureteroscopy was performed under general anesthesia and lithotomy position. Double J tube was removed by ureteroscopy. The 14 G trocar was used for the suprapubic bladder puncture. The POLY flexible ureteroscope was inserted into the ureter and renal pelvis by guidewire, manually push the water to keep a clear vision, used the YAG laser for lithotripsy. The Microperc operation was carried out under general anesthesia, indwelling catheter and prone position. The operation channel was established by B-ultrasound guided percutaneous renal puncture for the target renal calyx. Using a syringe manually push the water to keep a clear vision, used the YAG laser for lithotripsy. Result: Forty-one times and 47 sides of the kidney stones operation were performed in the flexible ureteroscopy group. A total of 32 times and 37 sides of the kidney stones operation in group Microperc. The operation time of flexible ureteroscope group was(38.1±16.5) min, perfusion fluid volume was(193±117) ml, postoperative hospital stay was(2.45±1.05) days, complete stone clearance rate was 73.17%, the complication rate was 34.1%; the operation time of Microperc group was(40.6±22.7) min, perfusion fluid volume was(210±133) ml, postoperative hospital stay was(2.29±0.92) days, complete stone clearance rate was 81.25%, the complication rate was 15.6%, the above indicators showed no significant difference between the two groups. On the second day after operation, the hemoglobin in the flexible ureteroscopy group decreased by(0.48±0.26) g/dl, and the volume of perfusion-drain fluid was(49.5±43.4) ml. In group Microperc, hemoglobin decreased by(0.65±0.33) g/dl, and the volume of perfusion-drain fluid was(20.8±13.6) ml.Conclusion: Both flexible ureteroscopy and Microperc technique show high safety and effectiveness in the treatment of kidney stones less than 2 cm in infants, but the complication rate of Microperc technique is lower.