It was pointed out that the sensitization of austenitic stainless steels due to weld heat cycling is pre-requisite to the stress corrosion cracking to occur in the piping systems in BWR plants. One of the techniques that can minimize the degree of sensitization by weld heat cycling is to reduce the carbon content in the materials. Mitigation of sensitization by control of weld heat input by the selection of adequate welding method is another useful technique to protect SCC. Electron beam welding attracts notice because of its high density of energy as well as the reliability of its weldments and economy, so the degree of weld sensitization is supposedly lowered. Sensitization characteristics of electron beam weldments were investigated synthetically by electro-chemical technique and stress corrosion cracking tests on type 304 stainless steel, and test results were compared with them by GTAW weldments. Moreover, similar investigations were performed on the some alternate materials, type 316 and type 347 stainless steels and those sensitization characteristics were compared with them of type 304 stainless steel. Finally, the efficacy of electron beam welding was certified from the view point of the suppression of weld sensitization.