The present invention provides a method for manufacturing a titanium dioxide photocatalyst composite material, and relates to a method for manufacturing a titanium dioxide composite ceramic material on which photoactive (photooxidative) apatite or another calcium phosphate monocrystal is partially deposited, wherein the method is characterized in promoting the following reactions by immersing titanium dioxide in an aqueous solution containing an excess of phosphorus ions and calcium ions in comparison with an artificial body fluid in order to fabricate a titanium dioxide photocatalyst composite material on which a compound composed of one or more apatite or other calcium phosphate Ca.sub.9(PO.sub.4).sub.6 monocrystals is partially deposited: (1) forming and aggregating calcium phosphate clusters and producing octacalcium phosphate; (2) converting the octacalcium phosphate into an apatite or other calcium phosphate Ca.sub.9(PO.sub.4).sub.6 monocrystal; and (3) growing the monocrystal.