A terminal and a brightness control method thereof are provided. The terminal includes an illumination sensor for measuring peripheral illumination of the terminal, a proximity sensor for detecting an object within a preset distance, a memory for storing a brightness table including data for controlling brightness of a display unit corresponding to the measured illumination, the display unit for displaying and for changing a brightness of the display unit under control of a controller, and the controller for controlling the display unit to change the brightness according to the measured illumination and the brightness table when the object is not detected. The terminal and brightness control method thereof provide a more suitable screen to a user.