Provided are a coating composition which provides a sheet with a visible light transmission property and a UV ray-blocking performance in addition to an excellent self-cleaning performance and a persistence thereof, a weatherability and a persistence thereof and a transparency and a sheet having a surface protective layer formed by the above composition. They are a coating composition comprising an ionizing radiation-curable resin and a hydrophilizing agent such as a silicate compound and alkyl silicate and a sheet having a surface protective layer formed by cross-linking and curing the above coating composition.