Induction motor instead of dc one has been applied widely for dc electric rolling stock because of the advantage of its utility and efficiency. However, further improvement of motor characteristics will be required to realize environment-friendly dc railway system in the future. Therefore, it is important to study more efficient machine applying dc electric rolling stock for next generation high performance system. For the first step, we reproduced torque characteristics of a dc motor that is utilized in an electric rolling stock, by analyzing specific current waveforms of dc substations. And then, we tried to reflect such torque characteristic to the conventional squirrel-cage induction motor based on the equivalent circuit. Furthermore, we tried to obtain the specification of high temperature superconductor induction/synchronous motor (HTS-ISM), which performance is similar with that of the above-mentioned conventional motors. We succeeded in showing the effectiveness of the introduction of HTS-ISM in DC electrified railway system.