PURPOSE: The titled composition having improved heat resistance, flexibility, and workability, obtained by blending a polyamide-imide resin in which a tricarboxylic acid is partially replaced with citric acid with another polyamide- imide resin obtained by a reaction in an organic solvent.

CONSTITUTION: (A) A phenolic solvent-soluble polyamide-imide resin obtained by reacting a tricarboxylic acid and/or its derivative (preferably trimellitic anhydride) containing ≥5mol% citric acid with a diisocyanate and/or its derivative (preferably aromatic diisocyanate) in a phenolic solvent is blended with (B) an aromatic polyamide-imide resin obtained by reacting a tricarboxylic acid and/or its derivative with a diisocyanate and/or its derivative in an organic solvent, to give the desired composition. After the resin B is prepared, it is preferably precipitated with an excess aqueous solution, filtered, dried, and used.