Fig. 1. shows FTIR spectra of original wool fabric and TCEP treated wool fabric. The peak at 2564.9 cm 1 in Fig. 1(a) was observed belonging to stretching vibration of the thiol groups produced after TCEP pretreatment. The peak of thiol group is not so obvious compared to original wool fabric spectra of Fig. 1(b) which may due to the limited quantity of disulfide bonds in wool fiber.