To provide a position estimating method in a radio communication system, capable of estimating the position of mobile units highly accurately without being influenced by the installation form of a base station.

The above problem is solved by the following procedures. Signals from each base station are received at a mobile unit to measure signal intensity for each base station; signal intensity from base station and base station identifying codes are combined to be delivered to a position estimating apparatus (S10); transmission power corresponding to the base station identifying codes and information on position are read (S12); signal intensity for each base station is normalized in accordance with transmission power that corresponds to its base station identifying codes and reference transmission power (S14); position estimation of a mobile unit is executed in accordance with the normalized signal intensity and the information on location position (S16).