"Arterial stasis chemotherapy" is a concept which summarizes administration methods of anticancer agents under the temporary blockade of the blood flow by any means. The drugs so infused is hardly diluted by blood flow, reaching the tumor tissue in high concentration and staying there much longer than that of administered by simple arterial infusion. "Arterial stasis chemotherapy" contains TAE (transcatheter arterial embolization) with gelatin sponge. TAE with ethiodol, TAE with microencapsulated anticancer drug, BOAI (balloon occluded arterial infusion), arterial administration of SMANCS/Lipiodol, intra-arterial administration of DSM (degradable starch microsphere) and so on. The authors confirmed that anticancer agents, which were soaked in gelatin sponge particles, densely stayed in the tumor for twenty hours after TAE using CT and iodinated contrast media. And we also confirmed a high level of the drug was present selectively in the tumor tissue for a longer time when it was given by BOAI than SAI using scintillation camera and Xe. After these basic studies, we applied TAE and BOAI on the patients with malignant tumors and got much better therapeutic effects than previous reports. We believe therapies based on the concept of "Arterial stasis chemotherapy" will prevail from now on.