A power transmitting apparatus with improved power transmitting efficiency and reduced lag time for shifting speeds can comprise a starting clutch mechanism configured to selectively transmit and cut off driving power of engine to wheels of a vehicle, a plurality of gear-stage clutch devices operatively positioned to transmit power between the starting clutch mechanism and the wheels, an input and an output of the plurality of gear-stage clutch devices configured at predetermined gear ratios, and a gear-stage selecting device configured to select any one of the gear-stage clutch devices in accordance with a vehicle operating condition and selectively set a gear ratio for power transmission from the engine to the wheels. The gear-stage clutch devices can comprise alternately arranged driving clutch discs and driven clutch discs, and hydraulic pistons. The hydraulic pistons can be configured to selectively engage or disengage the driving clutch discs and driven clutch discs such that driving power of the engine is transmitted to the wheels at a corresponding predetermined gear ratio when the driving clutch discs and driven clutch discs are engaged.