To achieve a location information detecting method for allowing reduction in overquality and communication load of the location information detecting system, simplification of the location information detecting system by using the foregoing location information detecting method, reduction in cost for the location information detecting system, and reduction in size and cost with regard to a communication terminal using the foregoing system.

There is provided the location information detecting method for communicating a predetermined area information to a base station by communication between the communication terminal device and the base station. In the location information detecting method, the communication terminal device includes a step for obtaining a first map divided into prescribed numbers from the base station in a data processing means to display the map, a step for selecting a first partial map from the first map, a step for transmitting to the base station data assigned in advance to the first partial map, a step for obtaining from the base station a nth (n is defined as a natural number larger than 1) map created by dividing the first partial map into predetermined numbers to display the nth map, a step for selecting a nth partial map from the nth map, and a step for transmitting to the base station data assigned to the nth partial map.