A communication system for communicating between a tire/wheel assembly and a body of a vehicle of a construction in which the tire/wheel assembly is supported by the vehicle body, has a i) wheel-side communication device that is mounted to the tire/wheel assembly and rotates together with the tire/wheel assembly, and ii) a body-side communication device that is mounted in a fixed position to the vehicle body. The communication system performs communication between the wheel-side communication device and the body-side communication device according to a predetermined rotational position of the tire/wheel assembly.