Chemoembolization is a technique by which the blood flow in the artery feeding a tumor is arrested and, at the same time, an antitumor agent is delivered in a high concentration to the target site in anticipation of a synergistic antitumor effect. Usually, this is a transcatheter technique. The embolic materials used to arrest the blood flow include gelatin sponge, Lipiodol, microcapsule, albumin microsphere, degradable starch microsphere and the like. Since the gelatin sponge and Lipiodol are available on the market, transcatheter oily chemoembolization (TOCE) using these two materials was performed in cases of hepatic tumor. In many cases of TOCE, adriamycin was used as an adriamycin solution Lipiodol mixture (adriamycin-in-oil emulsion). The cumulative survival rates for 100 patients with unresectable hepatoma treated by TOCE were 53.8% for one year and 36.5% for two years. Thus, improvement was observed in comparison with the cumulative survival rates of 104 patients who underwent hepatic embolization without Lipiodol (1 year, 45.2%, 2 years, 16.3%). Adriamycin-in-oil emulsion retained in the tumor as microemboli brings about the slow-releasing effect of adriamycin. The effect was demonstrated in the blood and tissue concentrations of adriamycin following TOCE.