A waterborne composition for forming protective coatings to provide, by a simple method comprising coating and drying onto a metal surface, a coating that is uniform with little unevenness and that has an excellent galling resistance and workability that are at least as good as the corresponding properties afforded by conversion treatment methodologies, contains water-soluble inorganic salt and smectite-type clay mineral. The lubrication performance of the coating can also be improved when said composition additionally contains a lubricating component.