1. A method for controlling the output of a voice guidance signal in a navigation system, comprising: searching for a travel route from a starting location to a destination of a vehicle; guiding the vehicle to travel along the searched travel route, and determining a current vehicle location if the vehicle is traveling, searching for a target location to be guided ahead of the traveling vehicle; generating a voice guidance signal for the searched target location to be guided; determining the priorities of a plurality of voice guidance signals in advance and outputting the voice guidance signals in sequence according to the predetermined priorities if the plurality of voice guidance signals conflict thereamong.