Abstract: A projection system includes a display device, a wireless presentation gateway, a computer terminal, and a portable device. The display device is used for displaying an image. The wireless presentation gateway is linked to the display device for transmitting image data to the display device. The computer terminal is linked to the wireless presentation gateway for transmitting the image data to the wireless presentation gateway. The portable device is connected to the computer terminal through a communication port for driving the computer terminal, the wireless presentation gateway, and the display device for performing an image display process automatically.