Provided is a method of performing time synchronization using a navigation device. The method includes: (a) performing time synchronization between a GPS satellite and a navigation device by receiving GPS signals by a navigation device from at least one GPS satellite; (b) establishing an interface between the navigation device and a time-using device; (c) setting conditions for transmitting time information to the navigation device; and (d) performing time synchronization between the navigation device and the time-using device by transmission of time information from the navigation device to the time-using device.