This invention, the inorganic solid phase, includes with the separate liquid phase and the particulate of organism compatibility and the organism disassembly characteristic polymer to option, it regards the composition for the fill possible cement. As for the said inorganic solid phase, mol constitution: (CP) 6 (CaO) y (SrCO3) z [CP, CaHPO4.2 H2 O and CaHPO4, Ca1-xSr xHPO4, bis Ca (H2 PO4) displays the blend of the equimolar blend of 2 H2 O and CaO or 2 kinds or 3 kinds of the said chemical compound, it is y+z=41. ] The blend of the powder which it possesses is included. Ratio L/P [capacity of the liquid phase/weight of the inorganic solid phase] at least is 0.4mL/g. These, as bone substitution ones, have use.本発明は、無機固相と、別個の液相と、随意に生体適合性及び生体分解性重合体の微粒子とを含む、注入可能セメント用組成物に関する。該無機固相は、モル組成:(CP)6(CaO)y(SrCO3)z[CPは、CaHPO4・2H2O、CaHPO4、Ca1-xSrxHPO4、ビスCa(H2PO4)2・H2OとCaOとの等モル混合物又は該化合物の2種又は3種の混合物を表し、y+z=4±1である。]を有する粉末の混合物を含む。比L/P[液相の容量/無機固相の重量]は、少なくとも0.4mL/gである。これらは、骨置換物としての用途を有する。