PROBLEM TO BE SOLVED: To provide a dispersion of insoluble collagen fibers derived from fish scales where the collagen fibers are maintaining a fiber structure being the basic structure of collagen conformation in the fish scales, and the dispersion can be used as well as aqueous collagen solutions and further enables uses that aqueous collagen solutions cannot achieve, and to provide a method for easily and stably producing such a collagen dispersion from fish scales.SOLUTION: Provided is a method for producing from fish scales a collagen dispersion in which filamentous insoluble collagen of which major axis/minor axis ratio is 5 or more is dispersed in a solvent, which method comprises the steps of: acidifying and wetting decalcified fish scales breaking up the wet fish scales by mechanical shear force to break the shape of whole fish scales to obtain a preliminary dispersion and pulverizing the preliminary dispersion by using a wet milling apparatus of which mechanism is different from that used in the breaking up step.
