A method of electrodeposition coating which comprises electrodepositing a water-base electrodeposition coating composition comprising an ionic group-containing resin as a film-forming vehicle on an article to be coated and then heating the coated article to form a cured coated film; wherein the ionic group-containing resin contains a functional group selected from the group consisting of hydroxysilane and alkoxysilane groups, and can be cross-linked by the condensation reaction of the functional group, and a resin composition for a water-base paint, said composition comprising a resin containing a cationic group and a functional group selected from hydroxysilane and alkoxysilane groups as a film-forming vehicle.