To provide a method for electrostatically coating an insulation substrate using a conductive primer composition soluble in water and a water- containing organic solvent, having high conductivity and excellent film forming properties, having excellent capacity not generating separation and flocculation even during long-term preservation, capable of being simply applied to the surface of insulation matter such as plastic or the like because soluble in a solvent, especially water and the water-containing organic solvent, forming a conductive primer layer showing excellent water resistance by crosslinking and enhanced in the compatibility with a topcoat coating, electrostatic coating efficiency and adhesiveness.

The crosslinkable conductive primer composition contains a water soluble conductive polymer having a sulfonic acid group and/or a carboxy group, a solvent and a silane coupling agent as essential components and, if desired, contains colloidal silica, a polymeric compound and/or a colorant.