A coating solution comprising 0.1 to 35% by weight of an inorganic or organic polysilazane having repeating units represented by the general formula below and soluble in a solvent and 0.1 to 10% by weight of catalyst such as 4,4'-trimethylenebis(1-methylpiperidine) based on a pure polysilazane content. By applying the coating solution onto the surface of base materials such as metals, plastics, glass, ceramic, wood, cement, mortar, bricks, etc., a silica coating strongly adhered to the base materials can be formed excellent in corrosion resistance and anti-scratch properties and simultaneously excellent in characteristics such as abrasion resistant, long-lasting anti-fouling properties, wetting properties to water, sealing properties, chemical resistance, oxidation resistance, physical barrier effect, heat resistance, fire resistance and antistatic properties.
