The electrochemical corrosion properties of welded joints of H65 brass alloy by friction stir welding and manual arc welding were studied by measuring open potentials and polarization curves in 3.5% NaCl solution. The result shows that the corrosion resistance of the friction stir welded joint is better than that of manual arc welded joint, because microstructural refinement, homogenization and densification reduced the electrochemical heterogeneity of grains and grain boundaries. The tensile stress between the dezincification layer and substrate has great effect on the corrosion resistance of the manual arc welded joint