This study has focused on the influence of MIG welding parameters optimization on tensile strength and hardness tests has investigated on medium carbon steel. The main objective of this study is to minimize defect in weld through second order full quadratic regression model for predicting four optimal process parameters which are current, voltage, travel speed and gas flow rate to maximize tensile strength. Selection of Process parameters and their ranges were determined by the Literature survey & by taking the review of experienced people working on MIG welding machine. For this research work the methodology used 3D RSM mathematical model parameters using OA, ANOVA, Regression analysis for 22 samples, design of experiment are implemented to obtain optimum combination of input parameters at 95% confidence level. The MIG welding parameters are the most important factors affecting quality, productivity and cost of welding. This paper presents the influence of welding parameters like welding current, welding voltage, welding speed and wire diameter. A plan of experiments based on orthogonal array and analysis of variance (ANOVA) are employed to investigate the welding characteristics of medium carbon steel material and optimize the welding parameters. For ANOVA contribution for each factor and regression analysis determined predicted tensile strength is 384.759MPa minimum percent improvement for tensile strength is 7.776% difference is from 357MPa original material TS. For regression analysis of RSM optimum values parameter combinations are 192, 35, 17.52, and 14.54 for current, voltage, travel speed and gas flow rate respectively. Confirmation tests were also carried out by the welded product tested on universal tensile test machine for design of experiment after optimum parameter determination through nondestructive test and distractive test to propose the optimum parameter settings. The conclusion for this research work is optimal use of process parameters on weld bead products has improved tensile stress and hardness tests is widely applicable and valuable in metal manufacturing area. KEYWORDS: MIG welding, Process Parameter optimization, DOE method, orthogonal arrays, analysis of variance (ANOVA), Nondestructive Test, Distractive Test and RSM