A network positioning system comprising a plurality of terminals, a terminal positioning device, and a path search target device, the terminal positioning device being configured to position the terminals in a network, a plurality of sub-networks being connected hierarchically in the network and each having an intermediary device, and the path search target device being connected to any of the intermediary devices, the network positioning system creating terminal position information representing relations of connection between the intermediary devices and the terminals, characterized by the terminal positioning device includes: a path information reception unit configured to receive, from each terminal, path information listing intermediary device identifiers that identify each intermediary device in the network on a path from the corresponding terminal to the path search target device; a terminal position information creation unit configured to create, based on the path information received from each terminal, terminal position information representing relations of connection between the intermediary devices and relations of connection between the intermediary devices and the terminals; an inter-terminal path information acquisition unit configured (i) to specify, within the terminal position information created by the terminal position information creation unit, one or more terminals connected to the same intermediary device as a terminal group, (ii) to acquire, for each terminal group, inter-terminal path information listing intermediary device identifiers that identify each intermediary device on a path from a terminal to another terminal in the same terminal group, and (iii) to acquire, for each combination of different terminal groups, inter-terminal path information listing intermediary device identifiers that identify each intermediary device on a path from a terminal to another terminal respectively included in the different terminal groups; and a terminal position information adjustment unit configured to adjust terminal position information created by the terminal position information creation unit in accordance with the inter-terminal path information by removing, from the terminal position information, an intermediary device identifier identifying an intermediary device that does not transfer data by returning the data. a path information reception unit configured to receive, from each terminal, path information listing intermediary device identifiers that identify each intermediary device in the network on a path from the corresponding terminal to the path search target device; a terminal position information creation unit configured to create, based on the path information received from each terminal, terminal position information representing relations of connection between the intermediary devices and relations of connection between the intermediary devices and the terminals; an inter-terminal path information acquisition unit configured (i) to specify, within the terminal position information created by the terminal position information creation unit, one or more terminals connected to the same intermediary device as a terminal group, (ii) to acquire, for each terminal group, inter-terminal path information listing intermediary device identifiers that identify each intermediary device on a path from a terminal to another terminal in the same terminal group, and (iii) to acquire, for each combination of different terminal groups, inter-terminal path information listing intermediary device identifiers that identify each intermediary device on a path from a terminal to another terminal respectively included in the different terminal groups; and a terminal position information adjustment unit configured to adjust terminal position information created by the terminal position information creation unit in accordance with the inter-terminal path information by removing, from the terminal position information, an intermediary device identifier identifying an intermediary device that does not transfer data by returning the data.