The present invention provides a tire state variables management system where an external module can reliably receive data from a specific sensor module from which data is to be acquired when an external module transmits to the sensor module a command signal for requesting data transmission. Each sensor module 3 possesses a self-identifying code for distinguishing itself from other sensor modules; the command signal transmitted by the external module 2 includes the self-identifying code possessed by the sensor module 3 from which data is to be acquired; and the sensor module 3 is adapted to transmit the data only when the self-identifying code included in the command signal from the external module 2 coincides with the self-identifying code possessed by itself.