A video conferencing system is provided. The video conferencing system includes: a first communication device, configured to receive a video signal from a host, and convert the video signal into a first video stream; and a second communication device, configured to receive a second video stream of a scene captured by an image capturing unit, and receive the first video stream from the first communication device by using a wireless communication protocol, wherein the second communication device selects one of the first video stream and the second video stream according to a switching signal, and transmits the selected video stream to an electronic system, wherein when receiving the switching signal, the second communication device stops transmitting the selected video stream to the electronic system for a predetermined time period, and transmits header information of another video stream to the electronic system, thereby resetting decoding settings of the system.