A mobile station requests a start of positioning and receives a response of positioning from a positioning server, following which it informs the positioning server of its own station information and neighboring base station information gathered through searching the neighboring base stations. Thereby, the mobile station receives assistant information regarding GPS satellites to be captured based on a station location designated by the positioning server and then it measures a GPS signal and a base station signal such as an apparent signal delay. In the case that the positioning information collected as described above is sufficient for location computing, it displays the location computed by the positioning server. In contrast, in the case that the positioning information is insufficient, it displays "positioning impossible" without sending the positioning information to the positioning server.