A video signal transmission system for transmitting a plurality of color video signals and horizontal/vertical sync signals from a transmitter part to a receiver part through a plurality of signal transmission lines is disclosed. The transmitter part includes a modulating circuit for modulating the video signals by a modulation method based on a Manchester format and generating a plurality of modulated video signals including Non Return to Zero video data, a synchronizing circuit for performing Code Rule Violation processing of the horizontal/vertical sync signals to generate burst signal-like sync signals in synchronism with the modulated video signals, a mixing circuit for mixing the burst signal-like sync signals with some of the modulated video signals to generate a plurality of transmission signals numbering less than a sum of the numbers of the modulated video signals and the horizontal/vertical sync signals, and a transmission circuit for transmitting the transmission signals to the signal transmission lines.