Abstract: In order to improve the moisture permeability of polyurethane(PU) film and its serviceability,PU film manufactured by wet film forming process was modified by wool powder which was made through chemical and mechanical methods by researchers themselves.It was observed by microscopy that the particle size of the wool powder was not uniform with average size of 5.46 μm.The moisture permeability of the PU film modified by wool powder was improved evidently and enhanced with the increase of wool powder and time.The film thickness and wool powder dosage also affected the moisture permeability rate of the PU film.It exhibited a spatial relation between wool powder quantity,film thickness and moisture permeability.