Disclosed herein is a charging system using a wound rotor synchronous motor (WRSM), capable of reducing volume, weight, and cost of a vehicle increased due to an on-board charging circuit and increasing a battery charge capacity. The charging system using a wound rotor synchronous motor (WRSM) includes an inverter converting power of a battery into alternating current (AC) powers having a plurality of different phases, a WRSM having a plurality of stator coils each receiving AC power of a different phase and a field coil forming mutual inductance with the plurality of stator coils and installed in a rotor to form a magnetic flux using power of the battery, and a controller controlling the battery side and the field coil side are insulated from each other in a charge mode in which grid power is applied to the field coil side of the WRSM.
