 This investigation studied the effect of different alkali metal and alkaline earth metal hydroxides on the chemical composition, secondary structure, and fiber morphology of wool using various analytical techniques such as amino acid analysis, elemental analysis, carboxylic content, acid and base combining capacity, ureobyssal fight and alkali solubility, FDR spectroscopy, thermogravimetric analysis, differential scanning calorimetry, x-ray diffraction pattern, and scanning electron microscopy. The results indicate that the effect of the used alkalis on wool is not similar, with cysteine, glycine, and basic amino acids being the most affected species in the treated wool. Some elimination reactions such as decuboxylation, desulfidration, and deamination were involved during alkaline treatment of wool. The secondary structure of wool treated with senior OH2MBAOH2 was changed from the helical structure into the sheet form. This article was authored by Amor Butoleb, Esmawafi, Sivines, and others. We are article.tv, links in the description below.