The effect of Sb on the corrosion resistance of low-alloy steels in a simulated polluted marine atmosphere was studied by electrochemical testing and weight loss measurements. The results showed that the addition of Sb could improve the corrosion resistance, which was confirmed by the increased polarization resistance of the steels that contained Sb. X-ray photoelectron spectroscopy analysis of the surfaces indicated that Sb participated in the formation of corrosion products and formed Sb₂O₅ in the rust layers. In addition, the precipitation of Sb₂O₅ with iron oxyhydroxides made the rust layers more uniform and compact, which provided the Sb-containing steels with better corrosion resistance than the Sb-free Steel.