As a fundamental study of efficacy of intra-arterial administration using ADM, ERB and MMC for prophylactic treatment of liver metastasis after hepatectomy for liver cancer, the pharmacokinetics of three drugs (ADM 10mg (n = 5), ERB 20mg (n = 3) and MMC 6 mg (n = 3)) were studied in patients who underwent hepatectomy after intra-arterial injection. The hepatic extraction calculated from the areas under the plasma concentration time curve of both administrations was 40% in ADM, 60% in ERB, and 0% in MMC. From these findings, it is suggested that intra-arterial administration could reduce by half the systemic toxic side effects of ADM or ERB, but the advantage of intraarterial infusion of MMC was not obvious.