The purpose of this study was to elucidate the availability of hydroxyapatite (HAp) granules as a chemoembolic agent in chemo embolization therapy. A mixture of adriamycin (ADM) and an embolic agent (HAp, Lipiodol) was injected via hepatic artery in normal Wistar rats. Then the concentration of ADM in the liver serum transaminase level were measured serially. The remaining ADM in the liver was higher in groups with HAp granules than the others. The serum transaminase, however, were lower in the HAp groups. There are some advantages of HAp using as a chemo embolic agent. (1) HAp is a physiological biomaterial and seem to be safe for human. (2) HAp granules injected into the liver are easily detectable by X ray and ultrasonography. (3) HAp granules have a large surface area and this characteristic is suitable for a carrier of drugs. It is concluded that HAp granules have some necessary prerequisites for a chemo embolic agent and the application to clinical practice may be expected.