Abstract: The invention discloses a mobile device for monitoring a vehicle path. The mobile device includes a setting module, a satellite-positioning module, a determination module, and an alarm module. The setting module is configured to set a preset route from a starting point to a destination. The satellite-positioning module is configured to receive a satellite-positioning signal. When the mobile device is located in a vehicle, the determination module is configured to determine whether the vehicle is driving along the preset route based on the satellite-positioning signal. When the vehicle deviates from the preset route for a default alarming time, the alarm module is configured to perform an alarm action.