A system for assisting fuel-efficient driving includes a storage unit for storing a shift pattern map, a collection unit for collecting the driving state information of a vehicle, a driving state calculation unit for calculating a current driving state and a target driving region on the basis of the information from the collection unit and the shift pattern map, and a display control unit for displaying the current driving state and the target driving region on a display to make it possible to compare the current driving state and the target driving region on the basis of at least acceleration or speed.