Electromagnetic interference (EMI) is an unavoidable part of the application of power electronics to the traction circuits of railway vehicles. As it is particularly difficult to reduce the noise level radiated by EMI from various types of equipment and cables, we replaced ordinary inverter-motor cables with shielded cables and investigated their effect on noise reduction. The results verified a reduction effect exceeding 10 dB at 100 kHz with shield bonding at both ends. The shielded cables are effective in reducing noise on traction circuits in particular such as jumper cables or motor leads for which other noise reduction methods are inapplicable.