1. A method for searching a polygon object for a navigation system, comprising the following steps of: finding a center point of a polygon object where the polygon object is a two-dimensional topological object expressed in a map database of the navigation system; creating a data table which arranges information on the polygon objects in the map database of the navigation system based on polygon names when the polygon object has not been associated with points of interest (POIs) in a map database of the navigation system; creating a data table which arranges information on the polygon objects in the map database of the navigation system based on polygon locations where each of the polygon locations is defined by the center point of the polygon object; specifying a desired polygon object through a screen of the navigation system either by a polygon name or a polygon location; retrieving, by a processor, candidate polygon objects from the corresponding data tables that match inputs specified by the user and displaying a list of the retrieved polygon objects in a predetermined order on the screen; and determining the desired polygon object by repeating the above steps; wherein the polygon names and the polygon objects are correlated with one another in the data table.