Display, controlling method thereof and display system

The display device, its control method and a display system is provided. According to this display device, when the AC power is applied through the power supply and the power supply unit, connected to scan for available control device, determines a pairing (Paring) history for the retrieved control device, pairing for the control devices found in paired history If it is determined that the record does not exist, a control for booting the display device, and performing the pairing between the detected controlled device.