By different testing methods (electrochemical techniques, potential shift monitoring, and Environmental Scanning Electron Microscope), this research evaluates the stray current corrosion of steel rebar in different layouts. The more significant corrosion state is observed when the steel bar is parallel to stray current flow, compared to the situation as a steel bar is vertical to the stray current. These outcomes are further clarified by the recorded level of stray current picked-up by steel rebar. It is found that the level of current actually picked-up by the steel rebar is decreasing. At the instant when the stray current supply is just turned off, an opposite current flow (back flow) is recorded. Besides an expansion of the database for monitoring stray current interference on reinforced concrete structures, the recorded results can be the basis for better understanding the process of stray current interference.