In this study, we used scanning electron microscopy and transmission electron microscopy to investigate cuticle layer keratinization from the hair root of hair follicles. The cuticle layer composed of 6 cuticular cells involved in keratinization. During the keratinization of the cuticular layer, the first process was the firm formation of an intercellular membrane complex, the same structure that is observed in a normal hair shaft. Destroyed nucleus and swollen mitochondria as well as debris of rough endoplasmic reticulum were observed in the cytoplasm of cuticle cell. Karyolysis, a process indicating nuclear destruction, but not karyorhexis or pyknosos, was observed. In an A layer and exocuticle zone, keratin proteins of granular sphere clustered and affiliated each other, followed by the formation of a long band with high electron density along the cell membrane. The thickness of cuticular cell in the process of keratinizing was 1~2 μm in diameter. It is twice or quadruple thicker than cuticular cell of normal hair shaft. This is due to the incomplete loss of cytosol in cytoplasm.