Electrochemical corrosion behaviors of friction stir welding (FSW) and MIG(mixed inert gas) welding joints of 6082 Al alloy and parent material 6082 Al alloy were investigated in a solution of 0.2M NaHSO3 and 0.6M NaCl ,by using potentiodynamic polarization curve and electrochemical impedance spectroscopy(EIS) and scanning electron microscopy (SEM) observation. The corrosion rate of the FSW joint was less than those of MIG joint and the parent material; the corrosion potential of the FSW joint was more positive than those of MIG joint and the parent material, the corrosion current density of the FSW joint was less than those of MIG joint and the parent material, the polarization resistance of the FSW joint was bigger than those of MIG joint and the parent material. EIS Nyquist loops indicated that an inductive arc existed on the complex plane.SEM observation showed that a few shallow pits presented on the surface of the FSW joint, however, a large number of deeper pits emerged on the surface of the parent materials and MIG joint.