Abstract: The superfine wool powder modification of polyurethane(PU) can improve the moisture permeability of its membrane,but the mechanical properties of the membrane drops considerably.In order to enhance the waterproof and moisture permeability of PU membrane while retaining its mechanical properties,PU membranes were made through the superfine wool powder and the TiO₂ compound modification of PU.The effect of addition of the powders on mechanical,moisture permeable,hydroscopic and waterproof properties of the membrane was discussed.The results indicate that the superfine wool powder and the TiO₂ compound modification of PU is an effective approach to improve the moisture permeability of polyurethane membrane.