A shock caused due to a change in the direction of torque transferred to an output shaft is reduced. There is provided a control device for a powertrain including a drive power source that transfers torque to an output shaft connected to a wheel of a vehicle, and a rotary electric machine that transfers torque to the output shaft via a transmission. When electric power generation performed using the rotary electric machine is restricted, if torque that decelerates the vehicle is transferred from the drive power source to the output shaft, a control is executed so that torque that does not decelerate the vehicle is transferred from the drive power source to the output shaft, and a shift control over the transmission is executed.