PURPOSE: To obtain a collagen having improved solubility by injecting a collagen solution through a nozzle into a hydrophilic organic solvent to form a strand-like or membraneous product, drying the product and chopping or grinding the dried product.

CONSTITUTION: The production process comprises injecting a collagen solution of a concentration of 3-10 % through a nozzle into a hydrophilic organic solvent such as acetone or an alcohol of a concentration of 90 % or higher at an injection speed of 1-30m/min to form a strand-like or membraneous product, drying the product at about 60°C to remove the organic solvent and the water therefrom, and chopping or grinding the dried product to obtain dried particulate or powdery soluble collagen.