Abstract: A steel sheet coating having high corrosion-resistivity and paint-adhesivity can be obtained by applying a water solution of specific composition described hereinafter on a steel sheet, followed by drying; and exposing the coating to ultraviolet rays in an air atmosphere; said water solution contains a chemical compound which has been prepared by reacting a prepolymer of an epoxy resin with acrylic acid or methacrylic acid in order to introduce vinyl groups into the molecules of said prepolymer, another chemical compound of chromate or dichromate for chelation and a molybdenum compound as a stabilizer.