A system and a method for assisting vehicle driving are provided. The system may select and use an imaging device among a plurality of imaging devices within a smart phone possessed by a driver or a passenger in a vehicle and assist in driving. A system includes a smart phone configured to capture an image in front of a vehicle and an inner image of the vehicle using the plurality of imaging devices within the smart phone and select one of the plurality of imaging devices. The system also includes a controller configured to analyze image information provided from the plurality of imaging devices to operate the smart phone or control the vehicle.