Objective To analyze the risk factors causing postoperative urosepsis in ureter endoscopic lithotripsy without infection preoperatively, in order to make a more effective and safer preventive and therapeutic strategy.Methods From January 2010 to January 2015, 5 ureteral calculus patients undergoing ureter endoscopic lithotripsy with holmium laser were retrospectively enrolled in this clinical study. These patients suffered urosepsis postoperatively confirmed by the clinical presentations and laboratory Results, while they had no infection in their blood and urine preoperatively. Without delay, 5 patients were treated by anti-inflammation and anti-shock.Results The vasopressor drug was stopped gradually after 12-36 hours. The body temperature was recovered to normal in 2 or 3 days, and the blood and urine test Results were not abnormal in 7 days. At last, 5 patients were all cured.Conclusions Stone and operation themselves are potential factors to cause urosepsis after ureter endoscopic lithotripsy. Especially for patients who had not presented infection preoperatively, careful preparation preoperatively, corrective manipulation, low pressure irrigation, drainage and controlling time during operation, and early diagnosis, appropriate treatment postoperatively are the key to cure and prevent urosepsis.