Disclosed are: a composition for hard tissue repair comprising a monomer (A), a polymer (B) and a polymerization initiator (C), wherein the polymer (B) comprises a polymer powder (B-x) having an aspect ratio of 1.10 or more, and the cumulative proportion of the powder particles having an aspect ratio of 1.00 or more and less than 1.10 to the entire powder particles among the components contained in the composition for hard rissue repair is 75 cumulative % or less； and a kit for hard tissue repair having members in which the components of the monomer (A), the polymer (B) and the polymerization initiator (C) contained in the composition for hard tissue repair are encased in three or more divided groups in an optional combination.本發明揭示一種硬組織修補用組成物，含有單體(A)、聚合物粉末(B)及聚合起始劑(C)，聚合物粉末(B)含有縱橫比為1.10以上之聚合物粉末(B-x)，且硬組織修補用組成物中含有的各成分中之粉末粒子全體之縱橫比為1.00以上未達1.10之粉末粒子之累積比率為75累積%以下，本發明並揭示一種硬組織修補用套組，具有將此硬組織修補用組成物中含有的單體(A)、聚合物粉末(B)及聚合起始劑(C)之各成分以任意組合分成3個以上的部分而容納的構件。
