There is provided an automatic parking system according to an exemplary embodiment of the present disclosure. The automatic parking system includes: a smart key recognition processor recognizing a smart key positioned in a first area; a sensor unit acquiring images around a subject vehicle if the smart key is recognized, and converting the acquired image into external images and synthesizing the images; a parking space recognizing sensor periodically receiving the external images and sequentially comparing the consecutive external images using an image recognition technology to recognize parking areas; and a controller calculating a moving path between a current position of the subject vehicle and an optimal parking area among the parking areas and controlling the subject vehicle based on the moving path, in which the parking space recognizing sensor may detect the parking areas in consideration of a length and a width of the subject vehicle.