A 24-year-old woman, gravida 1 and para 1, visited our emergency center with massive vaginal bleeding for a day. She underwent Cesarean section(C/S) using Misgav Radah Israel Method, at local obstetric clinic 4 months ago. She showed clear mentality but hemostatic instability at arrival in our emergency center. We performed the central venous catheterization on right jugular vein and transfused 3 units of packed red blood cells (PRC). And then16-French Foley catheter was inserted into vagina and ballooned for hemostasis. In the laboratory tests after blood transfusion, the WBC, hemoglobin, platelet count, activated partial thromboplastin time and prothrombin time were 15,020/mm3 (4,000~10,000/mm3), 8.1 g/dL (12.0~16.0 g/dL), 306,000/mm3 (150,000~450,000/mm3), 31.3seconds (22.0~37.0 seconds), and 14.7seconds (10.0~14.0 seconds) respectively. The Abdomen aorta Angiographic Computed tomography demonstrated subtle tortious vascular lesion on the right side of the uterine body with large amount of blood clot in the vaginal cavity during transfusion. We could find out the cause of delayed postpartum bleeding from the vascular imaging. It resulted from the acquired vascular shunt between uterine arcuate artery and circulating artery after malposition of layers during C/S. During imaging work-up, blood pressure fell to 74/46 mmHg with drowsy mentality and vaginal bleeding was aggravated. So, we added to transfuse 5 units of PRC, total 8 units. As more transfusion, uterine artery embolization was promptly performed. Totally 13 units of PRCs and 8 units of FFP were transfused for 2 days. The patient maintained hemodynamic stabilization. Fortunately, she was recovered very well and discharged without complications in four hospital days. This case showed the value of vascular imaging and intervention in the initial management of delayed postpartum bleeding. First of all, the proper layer by layer suture technic when repairing the uterine wound during C/S is mandatory.