A pack chromizing process is a widely used surface coating technology that is employed to improve the surface hardness and the corrosion resistance of Fe-based metal bipolar plates for PEMFC systems. The improvement of the anticorrosion property was investigated. Thin metal sheets of 316L were used in the fabrication experiments and were chromized at 950 °C for 3 hours and the microstructure was investigated by means of scanning electron microscopy (SEM), X-ray energy dispersive spectroscopy (EDS), and X-ray diffraction. Chromized layer with an outer ( Cr,Fe)2N1-x and inner (Cr,Fe)23C6 and (Cr,Fe)7C3 phase were observed. Potentiodynamic polarization test were conducted by sweeping potential range from -0.5V to 0.8V in a 0.5M H2SO4 solution at 80 °C. The result of electrochemical test showed that the corrosion resistance of these Fe-based steel can be enhanced significantly by the low-temperature pack chromizing. The improvement in corrosion resistance has a close relation with the better chemical stability of the chromium nitride