Stress corrosion cracking (SCC) is one of serious damages occurred in power generating plants, petrochemical plants, and gas pipelines. However, it is not easy to detect and evaluate SCCs because their shapes are complex and they are usually initiated in the weldment composed of base metal, weld metal, and heat-affected zone. In this study, the direct-current potential difference method (DC-PDM) was applied to SCCs artificially introduced in plate specimens and the applicability of DC-PDM to their detection was discussed. It was found from the measurement results that the potential differences near SCC were higher than those away from SCC. This fact suggests that SCC is detectable by DC-PDM.