Problem to be solved: to provide a composition for hard tissue repair exhibiting excellent porosity in a soft lump (dough) state and a hard tissue repair kit.Monomer (a),A hard tissue repair composition comprising polymer powder (b) and polymerization initiator (c)；Among the components contained in the hard tissue repair composition, a composition for hard tissue repair wherein the cumulative ratio of powder particles having an aspect ratio of 1.00 or more and less than 1.10% in the whole powder particle is over 5.0% by weight；AndMonomer (a) contained in this hard tissue repair compositionEach component of polymer powder (b) and polymerization initiator (c) isA hard tissue repair kit having a member accommodated in three or more parts in any combination.No selection【課題】軟塊（生地）状態において優れた細孔侵入性を示す硬組織補修用組成物及び硬組織補修用キットを提供する。【解決手段】モノマー（Ａ）、重合体粉末（Ｂ）及び重合開始剤（Ｃ）を含む硬組織補修用組成物であって、硬組織補修用組成物に含まれる各成分のうち粉末粒子全体におけるアスペクト比１.００以上１.１０未満の粉末粒子の累積比率が５.０累積％以上である硬組織補修用組成物；並びに、この硬組織補修用組成物に含まれるモノマー（Ａ）、重合体粉末（Ｂ）及び重合開始剤（Ｃ）の各成分が、任意の組合せで３つ以上に分割されて収容された部材を有する硬組織補修用キット。【選択図】なし
