This present invention relates to a method of improving the quality of animal fibers collected from sheep, goat, llama, or alpaca by removing scales.Firstly, (a), an oxidizing catalyst is absorbed in the hydrophilic areas on the surface of a fiber, that is, the joint sections (2) of the scales (1) and the end cuticles (3). Then, (b), the fiber is immersed in a solution of a chlorinating agent or an oxidizing agent to decompose the scales rapidly by oxidation in order to remove the scales (1). Then, (c), the fiber is treated with a solution of a reducing agent. The above process (a) is carried out by processing the acid to be used as a catalyst in a solution of a simple salt consisting strong acid and weak base or in an acidic gas in order to absorb it to the bonded moisture of the sections (2) and (3), or by bonding to the hydrophilic areas of the section (2) and (3) in a solution containing transition elements, Mg, or Al as ions, or in an organic solvent in which said solution is dispereded, after producing chelete bonding of said metals.This present invention improves the quality of blended products with animal fibers or furs efficiently in a short time at a room temperature.