Abstract: Objective:To evaluate the efficacy and safety of ultrasound guided percutaneous nephrolithotomy(PCNL)with the aid of pneumatic and ultrasonic power in treatment of renal calculi.Methods:One hundred and twenty-eight cases of renal calculi were treated by PCNL combined with pneumatic and ultrasonic lithotriptic system(EMS Ⅳ)under ultrasound guidance.Results:The 24F standard percutaneous renal access was successfully established in all the cases,and two accesses were established in 8 of them.The operative time ranged from 40 to 150 minutes.The stone-free rate was 82.0%(105/128)after the first operation,and no serious complications occurred.Stones were found in 23 cases and 15 of them underwent the PCNL for the second time;the stone-free rate was 86.7%(13/15)after the second operation.The total stone-free rate was 92.2%(118/128).Severe hemorrhage occurred in 8 cases after the operation;6 of them were cured by conservative therapy and the other 2 were performed nephrectomy.No septic shock or death occurred.Conclusions:Ultrasound guided percutaneous nephrolithotomy combined with pneumatic and ultrasonic lithotriptic system is safe and effective for treatment of the renal calculi.It is worth popularizing.