In order to suppress slip/skid phenomena, we have already proposed an anti-slip/skid re-adhesion control system based on a disturbance observer, and have confirmed that this system drives the train with a high adhesion force utilization ratio. However, this system does not consider vibration in the actual bogie dynamics of electric commuter trains, even though tangential force estimation is affected by bogie vibration. Hence, the drive control system cannot determine the appropriate motor torque reference, and sometimes reduces the adhesion force utilization ratio. This paper proposes a new anti-slip/skid re-adhesion control system based on a disturbance observer considering the first resonant frequency of the bogie system. In order to confirm the performance of the proposed anti-slip/skid re-adhesion control system, the system was tested by numerical simulation. This paper presents the results of a numerical simulation using a 4M1C motor car model, which. has a sensorless vector control system. The proposed disturbance observer is found to he effective in suppressing the vibration of the estimated tangential force. The numerical simulation results show that the proposed adhesion control method has excellent performance. (C) 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 172(2): 37-46, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DO! 10.1002/eej.20974