A control system for a hybrid vehicle configured to prevent a reduction in the purifying performance of the catalyst in a predetermined operating mode. An operating mode of the hybrid vehicle can be selected from a first hybrid vehicle mode, a second hybrid vehicle mode, and a fixed mode. A controller that is configured to restrict a shifting operation between the first hybrid vehicle mode and the second hybrid vehicle mode via the fixed mode, when the purifying device is being warmed or the purifying device has to be warmed.