Abstract: A coating composition capable of forming a transparent coating having a high refractive index, excellent dyeing properties and scratch resistance on a transparent solid material, the coating composition comprising:(A) 100 parts by weight of an epoxy group-containing silicon compound or a partial hydrolysis product thereof,(B) 0 to 100 parts by weight of an organosilicon compound or a partial hydrolysis product thereof,(C) a metal oxide sol containing 0 to 130 parts by weight of at least one metal oxide selected from the group consisting of antimony oxide, tin oxide and titanium oxide,(D) 0.25 to 30 parts by weight of a polybasic carboxylic acid or an acid anhydride thereof, or a bisphenol compound, and(E) 0.01 to 30 parts by weight of a curing catalyst, or,a molded article formed by coating a transparent solid material with the above coating composition as a coating layer-forming component.