Abstract: The effects of welding technologies including gas tungsten arc welding,electron beam welding,laser welding and friction stir welding on microstructure and mechanical properties of magnesium alloy welded joint are summarized.The main problems during the welding process are reviewed.According to the characteristic of magnesium alloy welding,some effective methods of improving mechanical properties of the welded joint are put forward.The research direction of the welding technology are pointed out.