To assist a vehicle operator in performing turning maneuvers in an appropriate manner under all conditions, a vehicle driving assist system includes: an external environment acquiring unit configured to acquire information on external environment surrounding a vehicle; a display unit having a screen displaying the information on the external environment; a steering state acquiring unit configured to acquire a steering status of the vehicle; and an image processing unit configured to determine a predicted trajectory of the vehicle according to the steering status of the vehicle, and superimpose the predicted trajectory on the information on the external environment displayed on the screen, wherein in case the predicted trajectory happens to be a full circle, the image processing unit removes a far end part of the trajectory to be displayed so as not to be connected to a start point of the trajectory on the screen.