The sensitization temperatures of austenitic stainless steel are between 450 and 850°C. However, it is inevitable that the Gas Tungsten Arc Welding (GTAW) process has to be heated or cooled in this range. The ASTM A262-93a corrosion practice and effects of heat flow input and weld quench procedure on the sensitization are then studied. Corrosion behaviors are observed and shown from potentiodynamic polarization and AC impedance measurements Minimized the input of heat flow seems to be the most effective for its corrosion resistance. The employed sensitization measurements and studying results suggest that heat-generation control will be crucial for AISI 304 stainless steel in GTAW welding.