A motor-driven vehicle includes a vehicle frame and a driving device. The vehicle frame includes a main body and a retaining unit. The main body has a first connecting portion and a second connecting portion. The retaining unit includes a retaining plate disposed pivotally on the first connecting portion and having a free end rotatable to close and open a groove in the first connecting portion. The driving device includes a support frame that has a first engaging portion disposed within the groove, and a second engaging portion connected to the second connecting portion by a tongue and groove engagement. When the groove is closed, removal of the vehicle frame from the driving device is prevented. When the groove is opened, removal of the vehicle frame from the driving device is allowed.