There is provided a navigation system using a wireless communication system and a route guidance method thereof. In the navigation system, an information center searches out an optimum route between a present vehicle position and a destination referring to map data in its map database and generates route guidance data. A navigation terminal inside the vehicle calculates the present position of the vehicle, transmits the vehicle's current position information to the information center, receives the route guidance data, and announces a notification message. A wireless communication network connects the information center to the navigation terminal wirelessly.