An area to be estimated is sectioned to minute sections, the received signal qualities from a plurality of installed base stations (51, 52) are found, respectively in each of the minute sections, a difference between the received signal quality of each minute section and the received signal quality of a minute section adjacent to the above minute section is referred to as well as a change point at which a difference between a received signal quality used as a hand-over condition and the above received signal quality changes is detected so that an area in which a hand-over occurs can be accurately estimated. With this manner, there can be obtained a received signal quality estimation method capable of estimating an area in which a hand-over occurs very accurately in a mobile communication system.