The effect of two different techniques, including Argon tungsten arc welding (TIG) and CO₂ shielded arc welding, on the welding seam corrosion behavior of the 316L stainless steel, and whether or not the concentration of chloride ions affect the welding seam corrosion of the welding samples are explored. The samples are studied by the traditional electrochemical techniques, such as potentiodynamic polarization curve, electrochemical impedance spectroscopy, and scanning microelectrode technique which is self-assembly made by authors. In conclusion, it is indicates that the corrosion resistance of welding seam zone is lower than that of base materials in any situation. In the NaCl and FeCl₃ solutions with different concentration, the anti-corrosion performance of the Argon tungsten arc welding samples are better than that of CO₂ shielded arc welding samples. The conclusion is all verified by the three different techniques. Besides, it is also concluded that the corrosion resistant of the both welding samples and base materials are decreased with the increase of the concentration of chloride ions.