Provided is a vehicle driving-support apparatus (10), wherein an ECU (4) comprises an air-resistance distribution acquisition unit (41), a target running position determining unit (43), and a driving-support unit (44). The air-resistance distribution acquisition unit (41) acquires air-resistance distribution in the left-right and front-rear directions of the vehicle upon which it is mounted. The target running position determining unit (43) determines a target running position of the vehicle upon which it is mounted with respect to a preceding vehicle, using the air-resistance distribution. The driving-support unit (44) supports the vehicle upon which it is mounted so as to guide the vehicle to the target running position. Such a vehicle driving-support apparatus (10) can guide the vehicle upon which it is mounted, even when an area wherein a high aerodynamics effect by a preceding vehicle can be attained is deviated in the left-right direction of the vehicle, to a position in accordance with the deviation. This enables the fuel consumption rate to be improved effectively.