Navigation system and method for displaying map on navigation system

A method for displaying a map performed by a navigation system, the method comprising: defining a matching area of a numerical map to which a photomap is matched; extracting the photomap corresponding to the matching area from a map data storage; matching a reference point of the photomap and a reference point of the numerical map; matching a scale of the photomap in line with a scale of the numerical map; and performing a boundary treatment at an overlap area of the numerical map and the photomap that are matched.