A four-wheel drive vehicle comprising a clutch control system for the four-wheel drive vehicle, wherein: - in the vehicle one of the left and right front wheels (6, 7) and the left and right rear wheels (19, 20) are set as main drive wheels that are connected to a driving source, while the others are set as auxiliary drive wheels that are connected to the driving source via a clutch (8, 16, 80), - the clutch control system is configured to perform selective connecting/releasing of the clutch (8, 16, 80) and comprises a drive mode switching unit configured to perform a switching control of a drive mode of the four-wheel drive vehicle in accordance with a vehicle state, - the clutch (8, 16, 80) includes a meshing clutch (8, 80) and a friction clutch disposed separately in a transmission path on the drive branch side and in a transmission path on the auxiliary drive wheel side with a differential interposed in the driving force transmission system to the auxiliary drive wheels, wherein the meshing clutch (8, 80) is configured to release a driving force transmission system to the auxiliary drive wheels from a driving force transmission system to the main drive wheels by releasing the meshing clutch (8, 80), wherein the friction clutch allocates part of a driving force from the driving source to the auxiliary drive wheels in response to the clutch connection capacity, and characterized in that the drive mode switching unit is configured, - when the vehicle speed is lower than a predetermined threshold speed, to switch the drive mode to a connect four-wheel drive mode with the meshing clutch (8, 80) and the friction clutch connected; - when the vehicle speed is higher than the predetermined threshold vehicle speed and the required driving force of the driver is lower than a predetermined threshold required driving force, to switch the drive mode to a disconnect two-wheel drive mode with the meshing clutch (8, 80) and the friction clutch released, and - when the vehicle speed is higher than the predetermined threshold vehicle speed and the required driving force of the driver is higher than the predetermined threshold required driving force, to switch the drive mode to a stand-by two-wheel drive mode with the meshing clutch (8, 80) connected and the friction clutch released. - in the vehicle one of the left and right front wheels (6, 7) and the left and right rear wheels (19, 20) are set as main drive wheels that are connected to a driving source, while the others are set as auxiliary drive wheels that are connected to the driving source via a clutch (8, 16, 80), - the clutch control system is configured to perform selective connecting/releasing of the clutch (8, 16, 80) and comprises a drive mode switching unit configured to perform a switching control of a drive mode of the four-wheel drive vehicle in accordance with a vehicle state, - the clutch (8, 16, 80) includes a meshing clutch (8, 80) and a friction clutch disposed separately in a transmission path on the drive branch side and in a transmission path on the auxiliary drive wheel side with a differential interposed in the driving force transmission system to the auxiliary drive wheels, wherein the meshing clutch (8, 80) is configured to release a driving force transmission system to the auxiliary drive wheels from a driving force transmission system to the main drive wheels by releasing the meshing clutch (8, 80), wherein the friction clutch allocates part of a driving force from the driving source to the auxiliary drive wheels in response to the clutch connection capacity, and characterized in that the drive mode switching unit is configured, - when the vehicle speed is lower than a predetermined threshold speed, to switch the drive mode to a connect four-wheel drive mode with the meshing clutch (8, 80) and the friction clutch connected; - when the vehicle speed is higher than the predetermined threshold vehicle speed and the required driving force of the driver is lower than a predetermined threshold required driving force, to switch the drive mode to a disconnect two-wheel drive mode with the meshing clutch (8, 80) and the friction clutch released, and - when the vehicle speed is higher than the predetermined threshold vehicle speed and the required driving force of the driver is higher than the predetermined threshold required driving force, to switch the drive mode to a stand-by two-wheel drive mode with the meshing clutch (8, 80) connected and the friction clutch released.