In this work the effect of welding parameters on mechanical properties of S355JR structural mild Steel was studied using SMAW process. S355JR structural mild steel was used as a base metal and E6013 as filler electrode with Taguchi orthogonal array of L9 was used in this study. The research has been done using experimental method with sample size of nine .Nine experiments were conducted using Welding parameters like, voltage, current and speed used as input variables and tensile strength, hardness of weld zone and hardness of HAZ as the output response in this investigation. S/N ratio and ANOVA were performed to know the significant of the parameters and the optimal welding condition using MINITAB18 software. The maximum mechanical properties of the welded sample were obtained when welding the sample using optimal welding parameter conditions .The maximum tensile strength, hardness of weld zone and hardness of heat affected zone were obtained 494.47 Mpa, 269.77 VHN and 255.06 VHN respectively. From the investigation all of the parameters have effect on the mechanical properties of the base metal.