Objective The effects of various pharmacologic agents on flow of saphenous vein grafts(SVGs) had been studied both clinically and experientally,and a correlation between graft flow and early patency rate in SVGs had been demonstrated in previous studies yet[1,2].Prostaglandin E1(PGE1), which has strong vasodilatory ,endothelial-protective effect and antiplatelet activity, is clinically used to treat ischemia diseases such as peripheral arterial occlusive diseases[3].