The purpose of this study is to examine the effect of permanent wave formation and minimization of hair damage. The virgin hair as hair sample was divided in 6 hair pieces (Control, PW-1, 2, 3, 4, 5). 5 The formation of curl, S-wave and change of the physicochemical properties were observed in permanent waving hair pieces. Pre-treatment with alkaline EW (PW-4 and PW-5) was higher in the S-wave formation rate, the most commonly used thioglycolic acid with sodium bromate treatment (PW-1) was the lowest in the permanent waving hair pieces. Thickness and tensile strength of hair shafts in pre- and post-treatment with EW (PW-5) were the most high and thick. In contrast, the pre-treatment with alkaline EW (PW-4) was the lowest in two indicators. The water swelling and alkali solubility in pre- and post-treatment with EW (PW-5) were the lowest in all of permanent waving hairs, and alkaline EW pre-treatment hair was higher than the other permanent waving hairs. In conclusion, only the pre-treatment with alkaline EW may be very useful for the virgin hair and pre- and post treatment with EW for the damaged hair.