Abstract: An ionic liquid 1-butyl-3-methylimidazolium chloride which has a good solubility for wool keratin was employed as a pretreatment step in protease processing. The effect of IL pretreatment combined with protease process on the wettability of wool fibers and fabric was analyzed through wetting time, water uptake and contact angle tests. The results revealed that IL pretreatment could sufficiently improve the efficiency of protease processing. The wettability of wool samples after the combined treatments was improved. The water wetting time and contact angle of wool fabric decreased quickly while water uptake of wool fibers increased. The tests of weight loss and XPS showed that IL pretreatment improved the hydrolyzation efficiency of protease, and thus inducing more hydrophilic protein groups exposed.