This invention relates to a process for producing porous and composite materials comprising steps of: freezing a complex containing at least one calcium salt selected from calcium carbonate, calcium phosphate, and hydroxyapatite and collagen, at least a part of which is gelatinized; and then lyophilizing the resultant. The porous and composite materials obtained by the method of the present invention have large pore diameters, high porosities, and adequate mechanical strengths and biodegradability. Thus, they are suitable for implants such as bone fillers, drug carriers for sustained-release, and the like.