To provide a data transmission system capable of performing multi- point sampling and reducing generation probability of transmission errors without frequency-dividing clocks generated by a transmitter side to multiple and transmitting them to a receiver in the data transmission system for which a transmitter and the receiver are connected through plural data lines and clock lines.

The transmitter 1 converts serial data to parallel data and transmits the data to the receiver 7. The receiver 7 performs execution by performing conversion to the serial data with the center bit of sampling data for which the received parallel data are multi-point sampled as correct data. Also, the execution is performed by counting the '0' and '1' of the sampling data, performing majority judgment and converting the major one to the serial data.