A mobile communication method includes the following steps: several first base stations and at least one second base station are provided. Wherein, each of the first base stations can cover a smaller area than the second base station can. A registration signal is received from a mobile communication device. If the registration signal is received through one of the first base stations, service is provided to the mobile communication device through the first base station receiving the registration signal, and a first base station list, which includes information of the first base stations, is transmitted to the mobile communication device. The mobile communication device measures signal strength of the first base stations according to the first base station list. The mobile communication device transmits another registration signal to the first base station with the strongest measured signal strength.