Abstract: While the high-quality waterproof-permeability fabrics were produced,such additives as calcium carbonate,cellulose powder were usually added to polyurethane coating solution to improve the properties and reduced the cost of PU coated fabrics.The PU microporous membranes were prepared in mixture modified carboxymethyl cellulose.The effect of modified carboxymethyl cellulose on the waterproof-permeability films was studied by testing some properties in using PMI,SEM and permeability instrument.