An aqueous thermosetting composition comprising an amino resin (A) obtained by addition dehydration condensation of an amino compound (a), an aldehyde (b) and an alcohol (c) and a urethane resin (B) obtained by polymerization of an isocyanate (d), a polyol (e) and an oxycarboxylic acid (f) having two or more hydroxyl groups. The aqueous thermosetting composition of the present invention contains both an amino resin and a urethane resin in a one-pack hardener, and the respective performances of the resins can be retained without any deterioration. Further, the aqueous thermosetting composition exhibits favorable dispersibility in water and excels in storage stability, so that it is useful in a wide spectrum of application fields, such as paint, ink, adhesive, coating material, binder and primer.