An electromagnetic energy harvesting device was studied based on the design parameters of an energy harvesting device for the power source of wireless sensors node on the rolling stock. The characteristics of the generated power by the energy harvesting device were tested using the laboratory equipment and a rolling stock (a high-speed train). First, a cantilever beam energy harvesting device, which allows for easy adjustment of the length according to the frequency and the power according to the cantilever beam materials, was researched. In addition, the new design for a practical resonant energy harvesting device for the railroad system was performed. To realize the performance of the practical resonant energy harvesting device, the generated power characteristics of the energy harvesting device were tested according to the moving displacement, the number of coil turns, and the initial coil displacement between the coil and magnet. The evaluation of the performance of the manufactured resonant energy harvesting device for the railroad system, which the parameters were determined based on the test results, was conducted under real driving conditions in the high-speed train, which was traveling at 300 km/h. Finally, this study analyzed whether the power generated could be applied to the wireless sensor nodes for the railroad system.