PROBLEM TO BE SOLVED: To provide a radio communication system capable of smoothly controlling one agricultural machine from a plurality of portable terminals.SOLUTION: A radio communication system 1a includes a control device 6 which controls operation of a tractor 4, a data communication device 5a which is capable of performing radio communication and connected to the control device 6 via wired communication, and portable terminals 3 which can be connected to the data communication device 5 via wireless communication. The portable terminal 3 is configured to output a control signal for controlling the control device 6, and the data communication device 5a receives the control signal outputted from the portable terminal 3 and includes a control signal discrimination part 54a which discriminates whether to output the received control signal to the control device 6.
