To provide a positioning system in an asynchronous communications net or the like which can perform positioning using a communications signal from a relay station.

The relay station 30 comprises a relay-station position information generation means for generating relay-station position information indicating the position of the relay station 30 and a timing-signal difference information generation means for generating timing-signal difference information indicating the difference between a transmission timing signal included in a communications signal CS2 transmitted by the relay station 30 and a standard timing signal. The terminal 60 comprises a terminal-side relay-station information acquisition means for acquiring relay-station information including the relay-station position information and the timing-signal difference information from the relay station 30, a communications-signal receiving means for receiving the communications signal CS2 from the relay station 30, a reception-time information generation means for generating reception-time information indicating a time at which the communications signal has been received, and a communications-signal positioning means for positioning the terminal on the basis of the relay-station position information, the timing-signal difference information, transmission-time information, and the reception-time information.