PURPOSE: An additive resin composition for epoxy paint is provided to able to improve drying performance at low temperatures, hardness, and adhesion at the same time. CONSTITUTION: An additive resin composition for epoxy paint comprises a modified Mannich reactant of which viscosity is 500-3000 cps(25°C), amine value is 100-300 mgKOH/g, equivalent of active hydrogen is 100-500 g/eq, and has a solid content of 70-100 weight%. An epoxy paint composition comprises the additive resin composition, the hardener, and the epoxy type base material. The comprised amount of the epoxy paint composition is 1-20 parts by weight based on 100.0 parts by weight of a hardener, and the comprised amount of the hardener is 3-40 parts by weight based on 100.0 parts by weight of the epoxy type base material.