The corrosion behavior of Cu-alloys used for marine propeller, including Mg-Al bronze (MAB), Ni-Al bronze (NAB) and Mn brass (MB) in 3.5%NaCl solutions with different pH values (2, 4, 6.8, 10, 12) was assessed via long-term mass change measurement, electrochemical test, and corrosion morphology observation. The results show that the corrosion rate of the three Cu-alloys is the highest when the solution pH = 2, this may be due to the severe dissolution of κ phase and preferential corrosion of β/β′ phases. When the solution pH = 4, 6.8 and 10, the corrosion mass loss rate of the three Cu-alloys is close, and for the solution pH = 12, the three Cu-alloys exhibit passive behavior with the least mass loss. MAB presents the highest corrosion rate and the worst corrosion resistance in any test solution. The mass loss rate of NAB in the solution of pH = 12 is close to that of MB, while the mass loss rate in other solutions is the lowest. After long-term immersion in the solution of pH = 6 and 8 respectively, the corrosion products film formed on the NAB surface exhibits the best protectiveness. In the solution of pH = 12, passive films may form on the surfaces of the three Cu-alloys, and their impedance increases rapidly with extended immersion time. The ranking order of the protectiveness of passive films is as: MB, NAB and MAB from high to low, which consistent with the mass change measurement results.