A system for estimating a driving intention of a vehicle driver comprises a vehicle surroundings detection device for detecting the vehicle surroundings, an operational input detection device for detecting operational input by the real driver, a first imaginary driver operational input calculation device for calculating the required operational input by a first method based on the vehicle surroundings in order to execute the driving intention of each imaginary driver for multiple differing imaginary drivers, a second imaginary driver operational input calculation device for calculating the required operational input by a second method that differs from the first method based on information differing from said vehicle surroundings in order to execute the driving intention of each imaginary driver, an imaginary driver operational input selection device for selecting either the operational input of the multiple imaginary drivers computed by the first driver operational input calculation device or the operational input of multiple imaginary drivers computed by the second driver operational input calculation device, based on the running condition, an operational input degree of similarity calculation device for calculating each degree of similarity between the operational input of multiple imaginary drivers and the operational input for the real driver, and a driving intention estimation device for estimating the driving intention of said real driver based on the multiple operational input degree of similarity.