A control device for a hybrid vehicle, comprising: an internal combustion engine and an electric motor mounted on a vehicle; a drive wheel driven by at least either one of the internal combustion engine and the electric motor; a power generator, connected to the internal combustion engine via a transmission, for generating electric power by being driven by the internal combustion engine; a secondary battery for storing electric power generated by the power generator and supplying the stored electric power to the electric motor; a clutch interposed between the internal combustion engine and the drive wheel and adapted to engage/disengage power transmitted from the internal combustion engine to the drive wheel; a vehicle speed sensor adapted to detect a vehicle speed of the hybrid vehicle; a mode switching control unit for switching between a series mode in which the drive wheel is driven by power generated by the electric motor by using the electric power supplied from the secondary battery and from the power generator by disengaging the clutch and a parallel mode in which the drive wheel is driven by power of the internal combustion engine and the power generated by the electric motor by using the electric power supplied from the secondary battery by engaging the clutch; and characterized in that said control device comprises further an operation state switching unit configured to switch, by an operation by a user, operation states of the vehicle between a first operation mode and a second operation mode in which a consumption amount of power of the secondary battery is suppressed more than in the first operation mode, wherein when the operation state switching unit is in the first operation mode, the mode switching control unit performs switching between the series mode and the parallel mode at a first vehicle speed (Vn) at which a maximum torque that is generable in the series mode becomes equal to a maximum torque that is generable in the parallel mode, and when the operation state switching unit is in the second operation mode, the mode switching control unit performs switching between the series mode and the parallel mode at a second vehicle speed (Ve) lower than the switching vehicle speed in the first operation mode, and the mode switching control unit prohibits the power generator from generating the electric power in the parallel mode. an internal combustion engine and an electric motor mounted on a vehicle; a drive wheel driven by at least either one of the internal combustion engine and the electric motor; a power generator, connected to the internal combustion engine via a transmission, for generating electric power by being driven by the internal combustion engine; a secondary battery for storing electric power generated by the power generator and supplying the stored electric power to the electric motor; a clutch interposed between the internal combustion engine and the drive wheel and adapted to engage/disengage power transmitted from the internal combustion engine to the drive wheel; a vehicle speed sensor adapted to detect a vehicle speed of the hybrid vehicle; a mode switching control unit for switching between a series mode in which the drive wheel is driven by power generated by the electric motor by using the electric power supplied from the secondary battery and from the power generator by disengaging the clutch and a parallel mode in which the drive wheel is driven by power of the internal combustion engine and the power generated by the electric motor by using the electric power supplied from the secondary battery by engaging the clutch; and characterized in that said control device comprises further an operation state switching unit configured to switch, by an operation by a user, operation states of the vehicle between a first operation mode and a second operation mode in which a consumption amount of power of the secondary battery is suppressed more than in the first operation mode, wherein when the operation state switching unit is in the first operation mode, the mode switching control unit performs switching between the series mode and the parallel mode at a first vehicle speed (Vn) at which a maximum torque that is generable in the series mode becomes equal to a maximum torque that is generable in the parallel mode, and when the operation state switching unit is in the second operation mode, the mode switching control unit performs switching between the series mode and the parallel mode at a second vehicle speed (Ve) lower than the switching vehicle speed in the first operation mode, and the mode switching control unit prohibits the power generator from generating the electric power in the parallel mode.