ObjectiveTo evaluate the clinical efficiency of balloon occlusion of the lower abdominal aorta in blood loss control during resections of pelvic or sacral tumor. MethodsFrom April 2006 to April 2010, 24 patients diagnosed as pelvic or sacral tumor in this hospital were collected. Balloon occlusion of the lower abdominal aorta to control blood loss was used in these cases. Balloon catheters were placed via femoral artery to occlude the abdominal aorta before operation. Resections of pelvic or sacral tumors were performed after occlusion of abdominal aorta, duration no longer than 60 min per occlusion, if repeated occlusions needed, 10－15 min release in between. Results Average operative time was 153 min (range 40－245 min) and average blood loss was 310 ml (range 200－650 ml) in this series, and the procedure helped in clearly identifying the surgical margin, neurovascular structures, and adjacent organs. The blood pressure were stable in all the cases. No postoperative renal function impairment was found in all the cases, no side injuries to adjacent organs was identified. One case complicated with thrombosis in iliac artery at same puncture side was successfully treated with catheter thrombectomy. ConclusionIntraoperative abdominal aorta balloon occluding in pelvic and sacral tumor surgical operation could reduce blood loss, and improve the safety of operation.