Composition for Metal Surface Treatment, Metal Surface Treatment Method, and Metal Material

Disclosed is a composition for metal surface treatment which enables to form a chemical conversion coating film which achieves sufficient foundation surface concealment, coating adhesion and corrosion resistance. Also disclosed is a method for treating the surface of a metal material wherein such a composition for metal surface treatment is used. Specifically disclosed is a metal surface treatment composition used for a treatment of a metal surface, which composition contains a zirconium compound and/or a titanium compound, and a polyamine compound having a number average molecular weight of not less than 150 but not more than 500,000. The polyamine compound contains not less than 0.1 millimole but not more than 17 millimoles of a primary and/or secondary amino group per 1 g of the solid content, and the content of the zirconium compound and/or titanium compound in the metal surface treatment composition is not less than 10 ppm but not more than 10,000 ppm in terms of metal elements. The mass ratio of the zirconium element and/or titanium element contained in the zirconium compound and/or titanium compound relative to the polyamine compound is not less than 0.1 but not more than 100.