[Problem to be Solved] To provide a porous composite that has excellent uniform dispersibility of OCP and that comprises OCP and collagen in a sufficiently mixed state； and a bone regeneration material comprising the porous composite. [Means for Solution] A porous composite comprising octacalcium phosphate and collagen, characterized in that in an image obtained by enlarging a 5.0-mm × 5.0-mm range of a plane of the porous composite 15 times with a scanning electron microscope (SEM), agglomerated particles of octacalcium phosphate have a fractal dimension (D) of 0.70 or more； and the area of c) portions consisting of collagen accounts for 5% or less of the total area of a) portions consisting of agglomerated particles of octacalcium phosphate, b) portions consisting of octacalcium phosphate microparticles and collagen, and the c) portions consisting of collagen.本發明的目的在於提供一種具有優異的OCP的均勻分散性且OCP與膠原蛋白被充分地混合之多孔質複合體以及含有該多孔質複合體之骨頭再生材料。本發明的多孔質複合體係含有第八磷酸鈣與膠原蛋白；在將多孔質複合體的平面之5.0mm×5.0mm的範圍以掃描型電子顯微鏡擴大15倍所得之影像中，第八磷酸鈣的凝集粒子的分形維數為0.70以上；在由：a)第八磷酸鈣的凝集粒子所構成的部分、b)第八磷酸鈣的微粒子與膠原蛋白所構成的部分與c)膠原蛋白所構成的部分之中，c)膠原蛋白所構成的部分的面積比率為5%以下。
