To provide primer compositions with which it is possible to form primer paint films with which the adhesion on metals such as iron, copper and the like, plated steel sheets where these have been plated, and especially zinc plated steel sheets, is excellent, with which the adhesion with the topcoat film when a polyamide (nylon) resin forms the topcoat film is also excellent and which has excellent gasohol properties in particular. A primer composition which contains (A) polyimide resin and/or polyester imide resin, (B) nylon resin beads, (C) epoxy resin and (D) hardening agent which is characterized in that the proportions with respect to the total mass of resin solid fractions of the (A), (B), (C) and (D) components included are from 10 to 30 mass% of the (A) component, from 79 to 20 mass% of the (B) component, from 10 to 30 mass% of the (C) component and from 1 to 20 mass% of the (D) component.