Abstract: Tea polyphenol obtained by the extraction from tea has an antibacterial effect. In methods for producing an antibacterial fiber by fixing the tea polyphenol to fiber, the object of the present invention is to provide a process for manufacturing an antibacterial fiber capable of exerting an excellent antibacterial performance without the use of metal chelates potentially causing metal allergy and environmental problems. In order to achieve the above object, the present invention manufactures an antibacterial fiber by a process comprising the steps of contacting fiber with or immersing fiber in an aqueous solution in which a cationic surfactant with a quaternary ammonium salt group, a water-soluble protein, and an alkaline compound are dissolved; and separating said fiber from the aqueous solution, to immerse the fiber in another aqueous solution containing tea polyphenol.