The passivation behavior of Fe–Al alloys (3.4, 10.4, 18.7, 19.4, 29.5, and 41.7 at % Al) and Fe–Al alloys (19.5 and 29.0 at % Al) with 5.1 at % Cr addition in 0.1 N H2SO4 is reported in this paper. The behavior has been evaluated by potentiodynamic polarization measurements. The results show the Fe–Al alloys, which the Al content of alloy exceeds 19 at %, have wide passivation regions with low passivation current. However, when the Al content of Fe–Al alloys exceeds this range, the increment of Al content has slight influence on passivation behavior compared with ternary Cr addition.