Vehicle clock synchronization using a navigation device

A vehicle clock synchronization method according to a navigation system is provided to revive precise situations of a vehicle at the time of accident by supplying precise time data to a vehicle black box by using a navigation system. A satellite navigation receiver(120) receives a navigation signal from one or more navigation satellites(110) to carry out clock synchronization between the navigation satellites and the satellite navigation receiver(22). Interface is established between clock-using devices(130,140) and the satellite navigation receiver(23). The satellite navigation receiver is set in the condition for transferring time data(24) and transmits the time data to the clock-using devices(25) so that the clock synchronization is realized between the satellite navigation receiver and the clock-using devices.