An electric motor driving system controls driving of an electric motor having windings of two or more phases each having open ends by using a pair of inverters. A control unit includes a first inverter control circuit that generates a first voltage instruction output to the first inverter based on a torque instruction and a second inverter control circuit that generates a second voltage instruction output to the second inverter based on the torque instruction. At least one of the inverter control circuits includes an electric power controller that controls allocation of electrical power supplied from a pair of power supplies to the pair of inverters, respectively, by either advancing or delaying an angle of a phase of each of vectors of voltage instructions in accordance with the target electric power instruction during execution of torque feedback control.