In a so-called dual power source and dual inverter system, in which a pair of first and second inverters controls and drives a motor that includes multiple windings of phases each having open ends based on electric power supplied from a pair of power supplies, a motor driving system capable of appropriately allocating the electric power supplied from the pair of power supplies to the pair of inverters is provided. The motor driving system includes a pair of first and second inverter control circuits to generate a pair of first and second voltage instructions supplied to the first and second inverters based on a torque command, respectively. One of the first and second inverter control circuits includes a power controller that controls sharing of the electric power supplied from the first and second power supplies in accordance with a target electric power instruction.