Objective To explore prophylactic bilateral internal iliac arteries balloon occlusion in treating pernicious placenta previa complicated with placenta implantation before cesarean section.Methods Data of 32 patients with pernicious placenta previa complicated with placenta implantation underwent prophylactic bilateral internal iliac arteries balloon occlusion(Balloon Group)were analyzed retrospectively.40 patients with pernicious placenta previa complicated with placenta implantation without treatment of prophylactic bilateral internal iliac arteries balloon occlusion(Control Group)were selected.The mean blood loss and infusion amount during the operation,operative time,newborn Apgar score were compared between the two groups.Results The mean blood loss and infusion amount during the operation,operative time,newborn Apgar score of balloon group was superior to the control group and the difference was significant.All mothers and infants were healthy detected by clinical checking on 3-6 months after birth.Conclusion Prophylactic bilateral internal iliac arteries balloon occlusion is a safe and effective treatment before cesarean section used in pernicious placenta previa complicated with placenta implantation,and worthy of further promotion.