The corrosion-resistance of a new kind of alloyed corrosion-resistant steel (10%Cr steel) was studied.The corrosion resistance of the passive film of 10%Cr steel naturally formed in simulated concrete pore solutions (pH=13.3) was evaluated by electrochemical impedance spectroscopy (EIS) and capacitance measurements (Mott-Schottky curves).Stainless steel and low-carbon steel were also employed for comparative purpose.Meanwhile, the features of the passive film for 10% Cr steel were studied by X-ray photoelectron spectroscopy (XPS).The results indicated that l0%Cr steel exhibited superior passive film to low-carbon steel, and its passivity resembled stainless steel due to the high charge transfer resistance and passive film resistance.In addition, the growth trend of the passive film of 10%Cr steel was analogous to that of SS steel, which was formed rapidly within the first day of immersion and slower during the following immersion time.Moreover,M-S curves and XPS results indicated that the composition and structure of the passive film for 10%Cr steel was similar to that of stainless steel.