To provide a plastic-coating galvanized steel sheet in which corrosion resistance at the edge faces and cross-cut parts is improved with high reproducibility without deteriorating its adhesion after working after plastic sheet coating.

As substrate treatment for plastic sheet coating, a galvanized steel sheet is subjected to surface regulation with a cobalt series in which the coating weight of Co is regulated to 20 to 40mg/mu2, thereafter, a nickel-adhered layer in which the coating weight of Ni is regulated to 0.01 to 4.0g/m2, and subsequently, chromate coating in which the total coating weight of chromium is regulated to 10 to 100mg/m2 is formed. In the case the chromate coating is added with vapor phase silica by 1 to 2 in the weight ratio of SiO/Cr, it is furthermore effective.