PROBLEM TO BE SOLVED: To provide a composition for repairing a hard tissue excellent in discharging property from a filling device (for example, nozzle discharging property from a cement gun) at a soft mass (fabric) state, and a kit for repairing the hard tissue.SOLUTION: There is provided a composition for repairing a hard tissue containing a monomer (A), a polymer powder (B) and a polymerization initiation (C), in which the polymer powder (B) contains a polymer powder (B-x) having aspect ratio of 1.10 or more, and cumulative ratio of powder particles having aspect ratio of 1.00 or more and less than 1.10 in whole powder particles in each component contained in the composition for repairing the hard tissue is 1.4 to 68 cumulative % or less, and a kit for repairing the hard tissue having a member in which each component of the monomer (A), the polymer powder (B) and the polymerization initiator (C) contained in the composition for repairing the hard tissue is divided into 3 or more and housed.SELECTED DRAWING: NoneCOPYRIGHT: (C)2020,JPO&INPIT【課題】軟塊（生地）状態において充填器具からの吐出性（例えばセメントガンからのノズル吐出性）に優れた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、重合体粉末（Ｂ）が、アスペクト比が１.１０以上の重合体粉末（Ｂ－ｘ）を含み、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１.４～６８累積％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
