A method for automatically executing a navigation software is provided. After a GPS device is activated, the GPS device receives a GPS satellite signal indicating a current location and decodes the received signal. Then, longitude/latitude data are obtained from the decoded GPS satellite signal by the GPS device. Then, corresponding navigation software is searched in the GPS device based on the longitude/latitude data. Finally, the found navigation software is executed, and the map data corresponding to the longitude/latitude data are automatically loaded. The method provided by the present invention is more user-friendly and the time spent in manually searching and calling the navigation software and loading the map data is effectively saved.