Disclosed are a resin composition (D) for coating obtained by reacting (A) an epoxy resin, (B) a butadiene-acrylonitrile copolymer having carboxyl groups or amino groups at both terminals of the molecule and (C) a bifunctional mononuclear phenolic compound, and an electrodeposition coating composition comprising the resin composition (D). The coating compositions have high adhesiveness to metal substrates and may form a high corrosion-resistance coat film having good flexibility, chipping-resistance and low temperature properties. The coating compositions are favorably used in car industrial field.