The present disclosure provides a parking assist system including: a rear object recognizer that recognizes a rear object existing behind a vehicle through rear sensors; a reversing controller that controls the vehicle to reverse until an entry rate to the parking space becomes a first reference value or more, and ends reversing control when a distance between the vehicle and the rear object becomes less than a second reference value; a rear object position storage that stores position information of the rear object and increases a count when the reversing control is ended on the basis of the distance between the vehicle and the rear object; and a system terminator that ends parking control when the position information of the rear object before and after the count is increased is substantially the same.