Control system for hybrid vehicles

A control device for a hybrid vehicle, which has; a first prime mover (1) and a second prime mover (7) for transmitting a power to a wheel (31); a power distribution device (10) for distributing the power of said first prime mover (1) to the wheel (31) and to a rotary device (6); a transmission (19) arranged on a power transmission route from said second prime mover (7) to the wheel (31); and a gear ratio control device (SL1,SL2) for controlling a gear ratio of the transmission (19); characterized in that comprising a sub control device (88,120) for controlling a status of transmission (19) to enable suppression of decline in a driving performance of the vehicle, even when the function of said gear ratio control mechanism (SL1,SL2) declines.