A vehicle driving assistance system includes a travel route generation system that acquires travel road information and obstacle information acquired by sensors and the like and generates the target travel route, on which a host vehicle travels, on a travel road. In the case where the host vehicle changes lanes, the system acquires information on the two peripheral vehicles, which exist near the host vehicle, on the change destination lane from the obstacle information, sets a target space, to which the host vehicle 1 should move, between the two peripheral vehicles on the change destination lane on the basis of this information on the two peripheral vehicles, predicts a future position of the target space on the basis of a moving speed of the target space, and generates the target travel route, on which the host vehicle travels during the lane change, on the basis of this predicted future position.