The ureteral injury is one of the significant complication of cesarean section.High risk factors include emergency caesarean section，history of caesarean section，hysterectomy during cesarean section，history of  hypogastric zone operation，pelvic infection，etc.The lower uterine segment，especially 1.5-3cm from UVJ，is the most common injury level，and more injuries occur on the left side than on the right.It is difficult to recognize the ureteral injuries intraoperatively.Postoperative diagnosis can be made by ultrasound，CTU or retrograde pyelography.Early recognition and repair of the ureteral injury are essential to the patient outcome and preventing late complications and reducing the cost.If the injuries are diagnosed postoperatively，the delayed operation can be performed between 6 weeks and 3 months after cesarean section if conditions permitted.The key to avoiding ureteral injury during cesarean section is prevention.This requires us to observe the course of labor closely and handle abnormal labor process in time to avoid emergency caesarean section after long trial.The incidence of ureteral injuries can be reduced by careful operation.