The topic of this graduate thesis is „Influence of parameters during MIG welding of aluminium alloy EN AW 1050“. The paper consists of a theoretical and an experimental part. The theoretical part presents the classification into wrought and casting aluminium alloys and their designation, The welding procedures of aluminum alloys are described, with an emphasis on the MIG procedure. Shielding gases and the choice of additional materials that significantly affect the properties of welded joints are listed. The AC MIG welding process and its advantages and disadvantages are described in detail. The most common irregularities that appear during the welding process are shown and described. In the experimental part, four samples of aluminum alloy AW 1050 were welded. The automated MIG welding process was used for welding aluminum sheets. The welding speed, gas flow and the distance of the nozzle from the workpiece were constant, while the type of gas and the thickness of the weld were changed. After welding, the samples were cut, ground and polished. After etching the samples, a macroscopic analysis of the samples was carried out in order to see the structure and properties of the welded joints. Based on the results, conclusions were drawn.