Wool fibres obtained from Polish Merino sheep was treated with orthosilicic acid [E. Wojciechowska, A. Wlochowicz, A. Weselucha-Birczynska, J. Mol. Struct. 511-512 (1999) 307]. The changes of the structure of keratin on the length of the hair staple, with the bottom (near skin) and the top parts separated, were analysed.The results obtained in the processes of dyeing and reducing of these fibres indicate the change in the keratin particle conformation. The changes in the structure of wool fibre were studied by means of Fourier-transform Infrared and Raman spectroscopy.