At the time of a change of a gearshift position SP from a neutral (N) position to a drive (D) position (step S220), when a vehicle speed V is not lower than a preset reference speed Vref1 (step S230: yes), the control procedure of the invention connects a power shaft with a driveshaft and attains an actual gear change of a transmission to a first speed (step S240). The reference speed Vref1 may be set to a slightly higher vehicle speed than an upper limit of a specific vehicle speed range having a potential for over rotation of a first motor by the gear change of the transmission to the first speed. When the vehicle speed V is lower than the preset reference speed Vref1 (step S230: no), on the other hand, the control procedure prohibits the connection of the power shaft with the driveshaft and the actual gear change of the transmission to the first speed. This arrangement desirably prevents the over rotation of the first motor caused by the gear change of the transmission to the first speed in the state that the vehicle speed V is lower than the preset reference speed Vref1.