A navigation system is used to automatically plan tours, which is characterized in that the navigation system comprises a storage module and a processing module, wherein the storage module is provided with a built-in electronic map which comprises a plurality of scenic spot information, the processing module receives a starting point information, a terminal point information, a starting time information starting from the starting point and a scheduled arrival time information for arriving the terminal point. And a route from the starting point to the terminal point is determined in the storage module, then at least one of scenic information, whether which is existed within a certain range on the route or not, is searched in the storage module, and a stay time of the scenic spot information is obtained. Further, at least one programmed scenic spot information, whether which is fit for stay from the starting point to the terminal point, is determined according to the route length, the starting time, the scheduled arrival time and the stay time of each of the scenic spot information.