PROBLEM TO BE SOLVED: To provide an organic hard tissue-like hardened substance and a powder composition and preferable use for the organic hard tissue-like hardened substance and the powder composition capable of forming a part of an organic hard tissue, having a characteristic of not remaining in an organism by dissolving or decomposing in an organic tissue other than an organic hard tissue, and which can be suitably used not just as an alternate material of an organic hard tissue but also as a drug carrier or the like for a DDS. SOLUTION: The organic hard tissue-like hardened substance is provided by mixing a biopolymer and a calcium phosphate-based compound, obtaining the powder composition by conducting a mixture crushing process P3 of crushing the mixture, and hardening the powder composition by adding and kneading a hardening controlling agent in the powder composition.