The magnetic pulse welding (MPW) were carried out with the 1060 Aluminum tube and AZ31 Magnesium alloy bar with different surface conditions. Quantitative analysis of the interface morphology of the obtained Al-Mg MPW joints was conducted. The heat production mechanism during MPW process was studied. The results show the MPW joints interface exhibits wave morphology which is the typical character of high velocity impact welding. The pocket type melting phase is distinguished at the joint interface by Mg bar with the smooth surface. However, the continuous melting layer is found at the joint interface by Mg bar with the rough surface. The bumps on the rough surface can catch more impacting jet, and disturb the transportation of the surface wave, which also block the heat lost process. So the interface temperature rises and the melting layer forms