A wheel drive system for independently driving right and left wheels of a vehicle is disposed between right and left wheels of the vehicle, and is comprised of a coaxial three-layer motor which includes an inner rotor, an outer rotor and a stator which are coaxially arranged; a first planetary gear reduction mechanism whose input is connected to the inner rotor, and whose output is connected to a first drive shaft of one of right and left wheels; and a second planetary gear reduction mechanism whose input is connected to the outer rotor and whose output is connected to a second drive shaft of the other of the right and left wheels. A reduction ratio of the first planetary gear reduction mechanism is greater than a reduction ratio of the second planetary gear reduction mechanism.