The present study examined the possibility of using spherical porous granules of hydroxyapatite (HA, Ca10(PO4)6(OH)2) composed of rod-shaped particles as the drug delivery system. The granules composed of rod-shaped HA were successfully prepared by an emulsion method and a hydrothermal treatment. When the rod-shaped granules were soaked in phosphate buffer salines containing lysozyme chloride or albumin, the granules of rod-shaped HA adsorbed more albumin than lysozyme. On the other hand, the HA granules prepared by a normal sintering method adsorbed little lysozyme chloride or albumin. The HA granules composed of rod-shaped particles are expected to be useful as carriers of negatively charged substances.