A study has been made of ion bombardment into the inner wall surfaces of tubes to develop hybrid type, small diameter artificial vascular grafts. Substrates used were polystyrene with an inside diameter of 2 mm and segmented polyurethane (SPU) coated glass tube with an inside diameter of 1.5 mm. Ne-ion bombardment into inner wall surfaces of tubes was performed at an energy of 150 keV with an average fluence of 4 × 10 14 ions/cm 2 at an incident angle of about 88.3°. The surface modification of inner wall surfaces was examined by X-ray photoelectron spectroscopy, which showed the presence of amorphous carbon structures in the inner surfaces of Ne bombarded tubes. Endothelialization was performed on the Ne-bombarded SPU coated inner wall of a glass tube, although it could not be done without ion bombardment. A femoral artery has been replaced by the new artificial graft, and exposed to blood for 24 hours. The new graft demonstrated 100% patency. The development of artificial vascular grafts will be feasible by ion beam modification of inner wall surfaces of tubes.