Abstract: The present invention provides a highly water-pressure-resistant and highly moisture-permeable waterproof sheet comprising a fabric and a wet coagulated polyurethane film thereon, a organophilic clay complex prepared by introducing a quaternary ammonium ion into the interlayers of a expandable phillosilicate being dispersed into the wet coagulated polyurethane film in an amount of 0.5 to 20% by weight based on the solid component of the polyurethane, and the waterproof sheet having a water pressure resistance of at least 5,000 mm and a moisture permeability of at least 8,000 g/m.sup.2.24 hr. The waterproof sheet is prepared by a process comprising dissolving a polyurethane in a solvent containing mainly a nitrogen-containing polar solvent, dispersing a organophilic clay complex which is prepared by introducing a quaternary ammonium ion into the interlayers of a expandable phillosilicate into the polyurethane-containing solution in an amount of 0.