A video conference system built in an internet protocol (IP) network is provided. The system has: a multimedia capturing unit configured to photograph and output a first video signal; a DECT telephone configured to receive sounds and output a first audio signal; and a video conference terminal apparatus, including: an audio processing unit is an audio codec; a video processing unit is an video codec; and a network processing unit for transmitting a first network packet consisting of first audio/video streams generated by the audio/video processing units to the IP network, wherein the network processing unit receives a second network packet consisting of second audio/video streams from the IP network, wherein the second audio/video streams are decoded by the audio/video processing units, respectively, to generate second audio/video signals, which are displayed on the DECT telephone and a display apparatus, respectively.