Resistance seam welding is a method that creates a weld between two ferrous or non-ferrous metals' facing surfaces. The seam can be either a butt or an overlap joint, and it's normally done automatically. The pressure and current are applied by two electrodes, which are commonly constructed of copper. The electrodes are frequently disc-shaped and rotate as the substance goes through. Motors may also be used to move or assist the electrodes. The motivation to use seam welding is the need for energy in the medical, food, beverage and transportation sectors is increasing at an exponential rate for automated, rapid weld procedure necessitates is to lose weight without sacrificing strength and to reduce defects. And due to the problem of limited resource and cost of a welding tool, there is a need to modifying the available resistance spot welding (RSW) process in to resistance seam welding (RSEW) machine. The optimization of process parameters of 304 stainless steel material for RSEW is presented in this research. The experiment was carried out on a 1mm thick sheet of 304 stainless steels. It was decided to use a lap joint arrangement. Pareto chart was used to select a process parameter i.e.; welding current, electrode force, wheel electrode rotating speed, and welding time. Using a single L9 orthogonal array and the grey relation analysis method, process parameters were also adjusted, with a larger is better quality attributes. Tensile, hardness, and liquid penetrant tests are used to analyze the mechanical properties of the weld joint at room temperature. The optimum level of test setup is: welding current of 3.2 KA, electrode force of 0.8 MPa, wheel electrode rotating speed of 8 rpm, and welding period of 200 cycles, according to the mean effect plot of GRG. ANOVA was conducted in order to investigate the significant process parameters. From the ANOVA, welding current and welding time were significant factors with percentage contribution of 67.42%, and 20.92%, respectively. Five confirmatory tests were conducted, and the results indicates that the mean grey relational grade of conformation test was 0.866667, and this result fall within the 95% confidence interval, hence the experiment is proven reliable. Finally, a modified RSEW machine gives a service at Bahir Dar institute of Technology, for Faculty of mechanical and industrial engineering in advance welding shop. Key words: 304 SS; Orthogonal array; ANOVA; Multi-objective.