The GA steel sheets with various strengths (590, 780, and 980 MPa classes) from which the Zn-Fe film was removed and 6061-T6 sheets were lap joined magnetic pulse welding under the conditions of gap length d of 1.17 mm and discharge energy W of 3.0 kJ. Before welding the GA steel sheets, a Zn-Fe film with a width of 5 mm was removed by grinding or acid treatment. In the case of acid treatment with dilute sulfuric acid, the film was removed within 3 minutes. On the other hand, when the film was removed by grinding, burrs were formed on the GA steel plate side. With either film removal method, the film was removed and a lap joint between GA steel sheet and 6061-T6 sheet was able to be achieved. This means that the joining position can be selected by magnetic pulse welding. The corrosion resistance of the lap joint sheets was investigated through salt spray test for 120-hours. The results showed that even under conditions where GA steel plates corrode, the weld interface did not corrode and bonding strength remained as well as before the corrosion test.