MIG welding is used in automotive industries which helps in good opportunity to reduce production costs, decrease vehicle weight and improve the strength of sheet metal joining. In this project, the objective is to study welding parameters used in joining two dissimilar metals. Aluminum 6 series and aluminum 7 series with thickness both 6 mm was weld together using MIG welding with tailor welded blanks method. In this project the voltage(V), wire feed(F) and gas pressure(P) are maintained according to the material used for MIG welding. By using design expert software MIG welding parameters are optimized to obtain good tensile strength. Response surface methodology type is used to optimization to study the parameters of MIG WELDING.