Ninety fresh umbilical cords of newborns were harvested and dissected. There were 86 cords with double arteries and single vein and 4 cords with only 1 artery and 1 vein. The outer and inner perimeter of single artery, double arteries and the vein was 3 8?0 3mm vs 6 2?0 3mm, 2 4?0 2mm vs 4 6?0 2mm and 10 0?0 4mm vs 10 8?0 4mm at empty and flatened state, respectively. The diameter of vein at 20mmHg filling pressure and single and double arteries at 80mmHg was 7 2?0 3mm, 4 8?0 1mm and 3 9?0 8mm, respectively. According to these values, various drainage and perfusion metal tubes were designed and evaluated both in vitro and in vivo. By using these tubes,extracorporeal circulation was established successfully via umbilical artery and vein in a newborn who suffered from cardiac arrest after birth. The results suggest that CPB through umbilical artery and vein is simple, practical and effective.