An electrochemical study on Al-brass alloy (76% Cu, 22% Zn, 2% Al) was conducted. The study focused on determining the corrosion susceptibility of the alloy in seawater in the absence and presence of manganese and chlorine in a stagnant condition. The results show that the addition of Mn from 0.5-5 ppm in seawater increases the corrosion current density of the Al-brass compared to samples tested only in seawater. In contrast, the addition of Cl-2 from 0.5-4 ppm slightly improves the corrosion resistance of the alloy in seawater.