A power assisted vehicle includes an auxiliary propelling device disposed to the frame body. The auxiliary propelling device has an auxiliary wheel and at least one transmission portion disposed in the auxiliary wheel. When two friction wheels of the transmission portion fasten to two sides of a friction ring of the auxiliary wheel, and the two power sources is in reverse to drive the two friction wheels for rotating, a wheel rim and a tire are further driven to produce rotations. The power assisted vehicle is therefore capable of self-propelled going forward without any external force. A processing device is further disposed in the power assisted vehicle. The auxiliary propelling device is then activated when the power assisted vehicle is at a specific speed. The energy consumption for the power sources is then reduced and the service life is extended. The transmission force distribution generated from the power sources is further adjustable. The usage of the power assisted vehicle is more efficient.