Nowadays, clinicians generally use the internal mammary artery, radial artery and the great saphenous vein for coronary artery bypass grafting. Different vascular construction, different reaction to vascular reactivities and different distribution of vascular smooth muscle receptors are all factors influencing spasms and early and late patency rate of bypass grafting. A clear understanding of the construction and function of bypass grafting contributes to the selection of a suitable bypass grafting method, and to improving its early and late patency rate.