The practical limitations of catheters used for infusion were studied by their types in 47 patients with hepatocellular carcinoma who were treated by Segmental Lp-TAE. For catheterization into the arterial branches of S5 and S8, a coaxial infusion catheter was helpful. However, a coaxial infusion catheter was seldom used for catheterization into the arterial branches of S6 and S7. For infusion into vessels having diameters of less than 1.9 mm at the tip end of the catheter, positive use of a coaxial infusion catheter is strongly recommendable. A Tracker-18 catheter was especially helpful for catheterization into the vessels of S5.