Abstract: To investigate the corrosion behavior of tin bronze in both natural and electrolytically treated seawater,open circuit potential-time curves,electrochemical impedance spectroscopy(EIS) and potentiodynamic polarization curves were analyzed,and the microstructures and the components of the sample before and after the corrosion were investigated by scanning electron microscope(SEM) and Energy Dispersive X-ray(EDX) methods. The results showed that the electrochemical behavior of tin bronze in treated seawater is similar to that in natural seawater,but the corrosion resistance of tin bronze in natural seawater is better than that in treated seawater.