In a shift system wherein the transfer of power is performed using a motor, the smaller the gear ratio difference is, the smaller can be made the motor output. However, the number of gears must be increased in order to reduce the gear ratio. As the number of gears increases, the problem of gear noise becomes more serious. It is necessary to prevent both an increase in the number of gears and an increase of the motor output. In a vehicular drive system according to the present invention, a shifting power unit is not merely provided between a first intermediate shaft and a second intermediate shaft of a shift system which has the two intermediate shafts, but one side of a shifting power unit is connected to a vehicle driving power unit, while an opposite side thereof is connected to a power transfer switching clutch so as to be connected to the first or the second intermediate shaft through a reduction mechanism, whereby the output of the shifting power unit is decreased while minimizing an increase in the number of gears.