Welding is the manufacturing method, which is carried out by joining two similar and dissimilar metals.MIG welding is one of the most widely used processes in industry. The MIG welding parameters are the most important factors affecting the quality, productivity and cost of welding.We studied input parameters of welding such as welding current, arc voltage, welding speed, root gap and output parameter are hardness, tensile strength, impact energy, and microstructure.This review is based on optimization techniques and analysis tools used by researchers to optimize the parameters.In this research paper a review has been presented on MIG welding. The previous literature has been discussed along with the future aspects included in the field of MIG welding.