Objective To evaluate the safety and efficacy of super mini-percutaneous nephrolithotomy (SMP) by ultrasound-guided renal access in pediatric with renal calculus.Methods From May to August 2015, 20 pediatric patients with upper tract stones underwent the SMP by ultrasound guidance.The patients aged 11-144 months , median age 31.5 months, The stone size ranged 0.8-2.5 cm, mean(1.48 ±0.59) cm.Among the 20 children, single pelvis stones were in 8, multiple stones in 10 and upper ureter stones in 2.All patients had no previous surgery treatment.The SMP system consists of a F6.0 -7.5 nephroscope and a modified F12-14 access sheath with suction-evacuation function.Nephrostomy tract dilation was performed up to F12-14 and lithotripsy procedure was performed by using pneumatic lithotripter.Nephrostomy tube or double J stent was placed only if clinically indicated.Results The stone size was 0.8-2.5 cm ,mean (1.48 ± 0.59)cm.Among the 20 children, there were 8 patients with single pelvis stone, 10 with multiple stones and 2 with upper ureter stones.All the patients were completed successfully without surgery conversion.Mean operative time ranged 6-40 minutes ,mean(17.6 ± 11.6) minutes.The stone free rate was 100％ after the evaluation in the postoperative day.The hemoglobin drop was 2-16 g/L,mean (7.6-± 4.1) g/L.No major complications occurred, neither patient required transfusion.The tubeless PCNL without double J stents and nephrostomy tubes placed were achieved in all patients.Only 14 patients had a ureter catheter placement for one day.The average hospital stay ranged 1-4 days, mean (2.4 ± 0.8) days.Conclusions SMP could be a safe and effective treatment for kidney stone up to 2.0 cm in pediatric cases with advantages of short recovery time, high stone free rate and no catheter placement.SMP could be the ideal procedure for children with upper urinary tract calculus.