A control unit of a rotary electric machine control system includes a stationary switching module and a transitional switching module. The stationary switching module switches over a control mode from a rectangular wave voltage phase control mode to an overmodulation current control mode by using a current phase of a smoothed current produced by filtering of high harmonic components on an actual current in a stationary operation state. The transitional switching module switches the control mode from the rectangular wave voltage phase control mode to the overmodulation current control mode by using the current phase of the actual current in a transitional operation state. The control mode is switched over by comparing the current phase of the actual current with a transitional switching reference line, which is preset separately from a switching reference line used for comparison with a current phase of the smoothed current.