Abstract: A video composite transmission system connecting a camera and a picture receiver of a picture transmitting device and a plurality of data terminals to a video switching network via an analog two path line transmitting an analog video composite signal. In the transmission part, it comprises means for shortening pulses of blanking and synchronizing the signal transmitted from the camera and thereby obtaining a blanking and synchronizing signal, in elongated back blanking porches of which are integrated and companded first digital multiplex data channels transmitted from first data terminals. Second digital multiplex data channels are also integrated and companded into the trace interval of each available black line of vertical blanking and synchronizing signal transmitted from camera.