Abstract: Minor Cu plays an important role in improving the corrosion resistance of metals. In this paper, the effect of Cu on the corrosion resistance of austenitic stainless steel and ferritic stainless steel in chloride solution is introduced. The effect of Cu on the corrosion resistance of nickel base alloys （Ni-Cr-Mo） in the oxidizing medium, reducing medium, oxidation-reduction medium, HF acid solution and FeCl₃ solution, compared the affection in different corrosion medium and summed up the reasons. Finally, the influence of Cu addition on corrosion resistance of magnesium alloy and Aluminum alloy is introduced. To deepen the understanding of the underlying principles through which Cu enhances the corrosion resistance of metallic materials,thereby promoting wider application of improved corrosion-resistant alloys by adding Cu.