To obtain a self-fusion paint composition capable of forming a coating film having excellent adhesion characteristics, high heat resistance, good fluidity, film-forming properties, low water absorption and high dimensional stability.

The composition contains a polyamide resin A composed of a repeating unit of formula (1a) and/or (1b) (wherein R1, R2 and R3 are each a divalent group C1 having an (un)substituted non-aromatic cyclic group in the principal chain or an (un)substituted alkylene group; Ra, Rb and Rc are each hydrogen atom or an alkyl group; and (R1 and Ra), (R1 and Rb), (Ra and Rb) and/or (R3 and Rc) may bind to each other to form a non-aromatic ring C2), wherein the repeating unit contains at least one of the group C1 and the ring C2.