A suspension of iodized oil and anticancer agent was injected into the portal veins of 20 rats with hepatic carcinoma. Oil drops were seen in tumor cell lines, small blood vessels inside the cancer nest, the sinusoid, and the central veins. After injection of oil suspension through the portal vein the distal small vessels were embolized and necrotic changes of tumor cells and their subordinate normal liver cells were observed. The results obtained in this experiment provided a good anatomical and pathological basis for treating liver cancers with the portal vein embolization with chemotherapeutic agents.