A vehicle driving device having a hydraulic circuit capable of efficiently supplying hydraulic pressure from an accumulator to a hydraulic servo in a short period while irreducibly minimizing the capacity of the accumulator. In the hydraulic circuit (50) provided for a gearless drive mechanism (30), the accumulator (56) is connected through an electromagnetic switch valve (55) with an oil path (62) connecting a clutch pressure control valve (53) with a manual valve (54). The oil path (62) has a one-way valve (71) for circulating oil only in a direction from the clutch pressure control valve (53) to the accumulator (56) and a clutch (C1) for forward movement. Then, the electromagnetic switch valve (55) makes an oil path (63) into a communicating state when an oil pump (51) is driven and makes the oil path (63) into a disconnecting state when the oil pump (51) is stopped.