The hydrogenation activity and sulfur-tolerant ability of nano- NiMo catalysts prepared by sol–gel method were investigated by hydrogenation of ethylbenzene containing thiophene. The results show that the adding of molybdenum has a profound effect on the structure and the sulfur-tolerant ability of nickel-based catalyst. The catalyst with MoNi ratio of 0.16 showed maximum hydrogenation activity and good sulfur resistance when compared to other catalysts. It seems that new hydrogen-adsorbed phase is formed at high temperature and the quantity of hydrogen adsorbed increases greatly when Mo is added to the nickel-based catalysts.