PROBLEM TO BE SOLVED: To efficiently and profitably obtain the subject composite material useful as a medical material, or the like, by homogeneously mixing collagen with silk protein.
SOLUTION: This silk protein/collagen composite material is obtained from the aqueous solution or dispersion of silk protein with collagen. The silk protein/ collagen composite material is preferably obtained in the form of film, gel, powder, or the like, from a mixture liquid. The mixture liquid is obtained by homogeneously mixing (A) a 0.1-10 wt.% silk protein aqueous solution or dispersion with (B) a 0.1-5 wt.% of collagen aqueous solution or dispersion. The component A comprises, for example, water-soluble silk fibroin obtained by dialyzing with a cellulose dialysis membrane an aqueous solution which is obtained by dissolving sericin adhered to the outsides of cocoon fibers extruded from silkworms or sericin-removed silk fibroin fibers in a neutral salt aqueous solution. The component B comprises a water-soluble or dispersible acylated collagen or acylated atherocollagen obtained by acylating the chemically reactive active sites of collagen molecule side chains or atherocollagen molecule side chains.