The corrosion behavior of painted steels with various surface conditions was studied using the galvanostatic polarization technique in a 3% NaCl aqueous solution at 25°C. The polarization curve obtained was of the mixed control type. At an initial immersion stage, i_corr was as small as 2×10^-5 to 2×10^-6A/m², but after a certain time (critical time), it increased sharply up to 10^-3A/m². The blistered area also increased. The corrosion resistance could be estimated from the critical time. It was in the order of polished-phosphated>rusted-phosphated>polished>rusted. The fastest corrosion reaction of the rusted painted steel could be attributed to the reduction of FeOOH in rusted layer to Fe₃O₄.