Provided is a collagen structure characterized by: comprising collagen fibers of 1 to 5 µm in average diameter； and has a water content of 0 to 15 (w/w)% and a collagen density of 50 to 800 mg/cm 3 . After generating collagen fibers by neutralizing an acidic collagen solution, the resulting solution is subjected to filtration or the like to form crude collagen fibers having a collagen concentration of 12 to 50 (w/v)%. The thus obtained crude collagen fibers are molded into a prescribed shape and then dried, thereby the collagen structure can be produced. Since the collagen structure is produced using, as raw material, collagen fibers that are formed by association of collagen molecules, the collagen structure has excellent cell infiltration property. Further, since the collagen density of the collagen structure is equivalent to that of in vivo collagen tissue, the collagen structure exhibits excellent tissue regeneration capacity when filled into a defective part in vivo. Therefore, the collagen structure can be preferably used as an artificial material for regenerative medicine and the like.
