Abstract: The characteristics of 316 L stainless steel which was pretreated under 30 % (mass fraction) of concentrated nitric acid and 98 % H2SO4+20 g/L KNO3 mixture respectively and the electrochemical corrosion of 316 L stainless steel in chlorine dioxide bleaching liquid were investigated by electrochemical testing and SEM analysis. From the results it showed that the pitting corrosion resistance ΔE of 316 L stainless steel could be up to 773 mV in the media of 25 ℃, 30 % HNO3 for 30 minutes. EIS spectra showed that 316 L stainless steel in chlorine dioxide bleaching liquid had double capacitive reactance arcs characteristics; the radius of capacitance reactance arc increased than those without passivation; the treated 316 L stainless steel at 60 ℃ appeared Warburg impedance; the outer and inner resistances of the passive film was larger than those without passivation. The corrosion rate of 316 L stainless steel by passivation in chlorine dioxide bleaching liquid lowered than the untreated nearly half, but the corrosion resistance is poor compared with titanium, and it can slow corrosion under certain conditions.