An aqueous resin composition comprising a neutralization product of an isocyanurate group-containing maleinized alkyd resin having an acid value of 5 to 65 in an aqueous medium, said maleinized alkyd resin being prepared by maleinizing an alkyd resin having an acid value of not more than 10 and a hydroxyl value of not more than 10 which is the product of condensation reaction of(A) 20 to 60% by weight of at least one of drying or semi-drying oils and fatty acids,(B) 10 to 45% by weight of at least one tris(hydroxyalkyl) isocyanurate,(C) 0 to 45% by weight of at least one polyhydric alcohol other than the component (B),(D) 10 to 45% by weight of at least one polybasic acid, and(E) 0 to 15% by weight of at least one monobasic acidand an aqueous emulsion resin composition obtained by emulsion polymerization of a radical polymerizable unsaturated monomer in an aqueous medium in the presence of the aforesaid neutralization product. The above aqueous resin compositions can give a coating having excellent corrosion resistance and fast-drying property.