The present invention provides a method for coating an inner surface of a polyvinyl chloride medical tube containing a plasticizer with an antithrombogenic material composed of a specific (meth)acrylate copolymer. The simple method of the present invention is capable of evenly and efficiently coating an inner surface of a polyvinyl chloride medical tube with a sufficient amount of an antithrombogenic material without causing appearance deterioration or uneven coating due to elution of the plasticizer. The method is performed by passing through a tube a solution that is prepared by dissolving an antithrombogenic material in a solvent composed of water and at least one alcohol that is adjusted to dissolve the copolymer of the antithrombogenic material but does not dissolve the plasticizer, then subsequently passing water through the tube, and finally drying the tube.
