Abstract: The present invention relates to a cationic electrodeposition coating composition comprising silica particles having pore volume of 0.44 to 1.8 ml/g and average particle size of no more than 10 ?m, the composition showing square root of diffusion coefficient (?Tc) of no less than 2.5 upon diffusing a solution onto a coating film therewith; a cationic electrodeposition coating composition comprising silica particles having pore volume of 0.44 to 1.8 ml/g and average particle size of no more than 10 ?m, wherein the composition shows minimum deposition pH of 11.90 to 12.00 during electrodeposition coating, and film resistance of 1,000 to 1,500 k?·cm2 at film thickness of 15 ?m and applied voltage of 240 V; and an article coated with such cationic electrodeposition coating composition.