Abstract: To provide a medical treatment device wherein the antithrombotic property and lubricity of a coating formed on the surface can be maintained in a stable state for a long period and also to provide a method for manufacturing the same. A mixture solution for coating wherein a copolymer of methyl vinyl ether with maleic acid anhydride, a quaternary ammonium salt and a polyether block amide dissolved in an organic solvent are applied upon the surface of a substrate comprising synthetic resin to form a coating and then urokinase and heparin are impregnated in the coating of the medical treatment device. The synthetic resin comprising the substrate is polyurethane, polyvinyl chloride, nylon or nylon elastomer. The quaternary ammonium salt is tridodecylmethylammonium chloride. An alkaline treatment is applied to a predetermined part of a substrate upon which a coating has been formed by application of the mixture solution.