An electronic device includes a display module, a function key, a motion sensor, a determination module, and a regulation module. The motion sensor is operable to acquire a coordinate of the electronic device. The determination module is operable to determine whether the electronic device is in the upright position based on the coordinate. The regulation module regulates backlight brightness of the display module when the function key is operative and the specific application is not executed when the electronic device is in the upright position.