The surface roughness of rail and wheel influences the shunting circuit resistance. On the first report, it was investigated into the relationship between the shunting resistance and the surface roughness of the rail tread, which was presumably and profoundly affected on the in adequate track circuit shunting. However, a few relationships were found between them. The authors proposed a newly investigation method to observe the rail treat using an electronic microscope for the rail surface conditions. In the report, the relationships were was described between the behavior of the track circuit shunting resistance and the rail surface condition investigated by the electronic microscope.