An on-train information transmitting/receiving system is provided that can be implemented in an environment with significant external noise and allows high speed transmission to be carried out between transmitter/receivers mounted in vehicles without having to develop a new jumper cable used between the vehicles while cost increase is prevented. A transmission path that connects transmitter/receivers 10 provided in vehicles included in a train to process train-related information in association with one another includes an inside vehicle interconnection cable 20 provided in a vehicle and a jumper cable interconnecting the vehicles. The jumper cable includes a plurality of shield electric wires 33 each produced by coating a conductor 35 with a shield 36, two such shielded electric wires 33 are paired to form the transmission path, the shields 36 of the pair of the shield electric wires 33 are connected with each other at both ends of the shield wires 33, and the shields 36 connected with each other are grounded at one end of the shield wires 33.