1. A driving assistance system for vehicle characterized by comprising: a traveling condition detection means that detects a traveling condition of a vehicle; a drive operation detection means that detects a drive operation by a driver; a drive diagnosis means that calculates an index for drive diagnosis based upon the traveling condition detected by the traveling condition detection means and the drive operation detected by the drive operation detection means, and diagnoses a drive operation of the driver from a calculated index; an information setting means that evaluates a drive diagnosis result by the drive diagnosis means in accordance with an evaluation criterion so as to set a content of information provision to the driver; and an information provision means that performs information provision to the driver with a content set by the information setting means.