A kit for bonding to biological hard tissues, containing a phosphorylated polysaccharide, a polyvalent metal salt other than phosphates, and a solvent. The adhesive composition for biological hard tissues provided by the kit for bonding to biological hard tissues is suitably used in for medical uses, such as cement for bones or dental cement. In addition, since the adhesive composition has excellent bio-absorbability, it is useful as fusion materials for artificial joint prosthesis, fusion materials for spine fracture, fusion materials for extremity fracture, filling materials for bone tumors in the region of orthopedics, filling materials and restorative materials at dental caries-defective sites, luting materials for prosthetic restorative materials such as inlay and crown, pulp-capping and lining materials, implant surface treatment materials, periodontal disease therapeutic materials, hyperesthesia preventive materials, dental pulp capping materials, substrates for DDS, substrates for systems engineering, and tissue bonding materials in the dental region.
