To compare the efficacy of intra-hepatic arterial infusion of anti-cancer drug under temporary occlusion of portal vein, the following two experiments were performed. 1. VX2 tumor cells (about 1 x 10(5) cells) were transplanted through the superior mesenteric vein of the rabbits, after 2 weeks, 4'-0-Tetrahydropyranyl doxorubicin (2 mg/kg, 2 ml) aqueous solution (THP) was administered into hepatic artery of rabbits with metastatic VX2 liver tumor. 2. THP was injected into hepatic artery under temporary occlusion of portal branch of median left lobe with metastatic liver. Then the THP levels of normal liver tissue and tumor of median left lobe and lateral right lobe. The THP levels of tumor under portal occlusion tended to be about 2.63-fold higher than without occlusion. These results suggest that hepatic arterial injection under portal occlusion is more useful to increase the levels of anticancer agents of metastatic liver tumor.