Magnesium alloys have an important role in our life. Magnesium alloys can be gnormal and liquefied, and because of their low density and good mechanical properties, they see wide application in the industry. They are mostly used in engine casings, pumps, filter vessels, rods, optical and x-ray devices, etc. Welding of magnesium alloys, magnesium physical properties, application and endurance problems, and potential dangers, control and quality assurance, and welding welding of Mg alloy and of course measures to avoid them are analyzed. All of these is very important to overcome the purpose of the correct and high quality use of Mg alloy in welding. In the introductory part, there are physical dispersions of magnesium and magnesium alloys as well as applications and problems whose knowledge is essential for further development of the subject. By elaborating the subject more closely, the welding of the Mg alloys themselves, the danger of welding, how to control and ensure the quality of the welds, and the possible mistakes that occur in the weld and how to avoid them will be explained.