The invention provides a room temperature curing weatherproof coating composition suitable for forming, on a room temperature dry condition, a curing film with excellent long-term weather resistance even in severe corrosion environmental conditions. The room temperature curing weatherproof coating composition and a method coating the coating composition are provided. The room temperature curing weatherproof coating composition comprises a multi-ingredient composition containing a main agent ingredient (I) and a curing agent ingredient component (II). The main agent ingredient (I) comprises polyamine (A). The curing agent ingredient component (II) comprises polyepoxide (B). The room temperature curing weatherproof coating composition is characterized in that at least one of the main agent ingredient (I) and the curing agent ingredient component (II) contains organic metallic compound (C), organic silicon resin (D) containing hydrolyzed silicyl, ultraviolet light absorber containing hydroxyl and/or light stabilizer (E) containing hydroxyl.