Hair is based upon the skin which enroll the body of high living animals and have multiple membrane structure. This study were used rats and carried out to find out the effects of commercial permanent wave products to skin which are composed of thioglycolic acid and bases. Results were as follows. Permanent wave penetrated to 3 hours later with steady state in skins and was not significant changeable after 20hr later. In case of neutralizer with thioglycolic acid lag time and permeability coefficient in healthy skin were 3.38hr and 0.96$mu extrm{g}$/$ extrm{cm}^2$/hr, in old skin were 3.14hr and 0.l28$mu extrm{g}$/$ extrm{cm}^2$/hr, and in wounded skin were 3.08hr and 0.157$mu extrm{g}$/$ extrm{cm}^2$/hr. In conclusion, lag time and permeability coefficient in old skin and wounded skin were faster than healthy skin. In vivo which was studied by general time and method of permanent wave. We found out that fine rinkle and rash of skin were changeable in the case of treating with permanent wave drugs than normal skin. Also, permanent wave drugs could induced rash and eruption at the skin by the naked eye.