Abstract: This paper studies the effects of different solution processes and artificial aging treatments on the microstructure, mechanical properties and inter-granular corrosion of Al-Mg-Si-Cu alloy by tensile test and inter-granular corrosion experiment. The results show that the temperature-incremental strengthening solution treatment increases the super saturation degree of alloy. The strengthening solution and two -step solution treatments are favorable to improve the precipitating and distributing of precipitated phase during the following aging, which in turn enhances the resistance of inter -granular corrosion. The alloy obtains high tensile strength and inter-granular corrosion resistance after strengthening solution and two-step aging. The ultimate tensile strength and the average corrosion depth of the alloy are 295 MPa and 39 μm, respectively.