The present invention provides a cationic electrodeposition coating composition that has excellent throwing power and that can form a thin film with excellent finish and anti-corrosion properties. The composition has a cationic epoxy resin (A) and a blocked polyisocyanate (B), the cationic epoxy resin (A) obtained by reacting an epoxy resin (A1) with an amino group-containing compound (A2). The epoxy resin (A1) having a catechol skeleton structure (a) and obtained by reacting an epoxy resin (a1) containing at least one epoxy group per molecule and having an epoxy equivalent of 180 to 500 with a phenolic hydroxyl group-containing compound (a2) containing at least one phenolic hydroxyl group per molecule in amounts wherein the ratio of the number of moles of epoxy groups in the epoxy resin (a1) to the number of moles of phenolic hydroxyl groups in the phenolic hydroxyl group-containing compound (a2) is 1.3 to 2.0.