Abstract: The invention discloses a system for detecting a peripheral device being installed onto an electronic apparatus. The peripheral device includes a cable, and the cable has M first pins, wherein a first detection pin is selected from the M first pins. The system includes a port and a delay circuit. The port has M second pins, and each second pin is corresponding to one of the first pins of the cable, wherein a grounded second detection pin is selected from the second pins, and the second detection pin generates a voltage signal in response to the first detection pin. The delay circuit is used for receiving the voltage signal and, after a predetermined delay time, for outputting a delayed voltage signal to the electronic apparatus. Accordingly, after receiving the delayed voltage signal, the electronic apparatus starts to detect the peripheral device.