PURPOSE: To provide a protective coating compsn. for preventing the discoloration (corrosion) of silver.

CONSTITUTION: A silicone-acrylic resin curable at the normal temp., e.g. one obtd. by compounding a vinyl polymer having reactive groups having basic nitrogen atoms with a compd. having an epoxy group and a hydrolyzable silyl group in the molecule in a specified ratio, is used as the basic film-forming component for preparing a coating compsn. The obtd. compsn., forming a coating film excellent in adhesive properties, transparency, moisture resistance, resistance to hydrogen sulfide, etc., and also in the persistence of those properties, is esp. useful for long protecting decorative silver goods and esp. silverized surfaces of electronic parts, lighting apparatus, etc., from discoloration and corrosion.