The purpose of the present invention is to provide a bone cement composition which can have desired biological activity performance and desired radiolucency while enabling the strength of a cured product thereof to be kept. A titanium oxide coating is formed on radiolucent particles to thereby produce composite particles, and the composite particles are added to a bone cement composition. The bone cement composition thus produced can be used suitably for the filling of a bone defect portion and the fixation of an artificial joint and in percutaneous vertebroplasty. The shape of each of the radiolucent particles is preferably granular, and the titanium oxide is preferably of a rutile type.
