The present invention discloses: a composition for repairing hard tissue, the composition including a monomer (A), a polymer (B), a polymerization initiator (C), and a contrast agent (X) having a volume average particle diameter of 3 μm or more, wherein the composition is excellent in intrusion into an adherend such as a cancellous bone, and excellent in adhesion to the adherend； and a kit for repairing hard tissue, the kit being provided with a member in which components of the monomer (A), the polymer (B), the polymerization initiator (C) and the contrast agent (X), which are included in said composition for repairing hard tissue, are accommodated such that the components are divided into three or more in an arbitrary combination thereof.
