To provide a method of forming a cured coating on the surface of a crystalline thermoplastic resin molding having excellent adhesion and appearance.

This method of forming a coating on a resin molding comprises the steps of roughening at least a part of surface of a crystalline thermoplastic resin molding, especially of polybutyleneterephthalate resin or polyphenylene sulfide resin molding, so that the surface roughness being 10 μm≤Rz≤40 μm (where Rz means an average roughness for 10 points), coating the roughened surface with two-pack curable resin composition, especially urethane resin composition or epoxy rein composition, and curing.