Abstract: Objective To summarize the experiences of pneumatic lithotripsy under ureteroscope for pyonephrosis due to calculus obstruction.Methods Twelve patients with pyonephrosis due to calculus obstruction were treated using endoscopic manipulation such as ureteroscopy,pneumatic lithotripsy and indwelling double J catheter. Results In the 12 cases,the ureteral calculi were cleared after one treatment in 10 cases,and the other 2 cases were cured by additional extracorporeal shock-wave lithotomy performed 1 to 2 weeks later.Conclusion Ureteroscopic manipulation is safe,minimally invasive and effective for the treatment of pyonephrosis due to calculus obstruction.