A mobile communication handover method of a mobile station from a cell subordinate to a first radio base station (eNB#0) to a cell subordinate to a second radio base station (eNB#1, HeNB#2, HeNB#3), comprising: a step of determining, by the first radio base station (eNB#0), whether the second radio base station (eNB#1, HeNB#2, HeNB#3) is a macro cell radio base station or a small cell radio base station according to cell identification information included in an E-UTRAN Cell Global Identity, E-CGI, which is included in a measurement report received from the mobile station; a step of transmitting, by the first radio base station (eNB#0), a first handover request signal, in which a part of the cell identification information is set as identification information of the second radio base station (eNB#1, HeNB#2, HeNB#3), to a mobile switching center when it is determined that the second radio base station (eNB#1, HeNB#2, HeNB#3) is the macro cell radio base station; and a step of transmitting, by the first radio base station (eNB#0), a first handover request signal, in which the cell identification information is set, as is, as the identification information of the second radio base station (eNB#1, HeNB#2, HeNB#3), to the mobile switching center when it is determined that the second radio base station (eNB#1, HeNB#2, HeNB#3) is the small cell radio base station, wherein the mobile switching center comprises a management unit configured to manage an entry including identification information of a radio base station and identification information of a tracking area, and the mobile communication method comprises: a step of transmitting, by the mobile switching center, a second handover request signal including the identification information of the tracking area to the gateway device (HeNB-GW) if a length of the identification information of the second radio base station (eNB#1, HeNB#2, HeNB#3) is a predetermined length and an entry including the identification information of the tracking area included in the first handover request signal is managed by the management unit even when an entry including the identification information of the second radio base station (eNB#1, HeNB#2, HeNB#3) included in the first handover request signal has not been managed by the management unit; and a step of transmitting, by the gateway device (HeNB-GW), a third handover request signal to the second radio base station (HeNB#3) designated by the tracking area included in the received second handover request signal and the identification information of the second radio base station, which corresponds to the identification information of the radio base station. a step of determining, by the first radio base station (eNB#0), whether the second radio base station (eNB#1, HeNB#2, HeNB#3) is a macro cell radio base station or a small cell radio base station according to cell identification information included in an E-UTRAN Cell Global Identity, E-CGI, which is included in a measurement report received from the mobile station; a step of transmitting, by the first radio base station (eNB#0), a first handover request signal, in which a part of the cell identification information is set as identification information of the second radio base station (eNB#1, HeNB#2, HeNB#3), to a mobile switching center when it is determined that the second radio base station (eNB#1, HeNB#2, HeNB#3) is the macro cell radio base station; and a step of transmitting, by the first radio base station (eNB#0), a first handover request signal, in which the cell identification information is set, as is, as the identification information of the second radio base station (eNB#1, HeNB#2, HeNB#3), to the mobile switching center when it is determined that the second radio base station (eNB#1, HeNB#2, HeNB#3) is the small cell radio base station, wherein the mobile switching center comprises a management unit configured to manage an entry including identification information of a radio base station and identification information of a tracking area, and the mobile communication method comprises: a step of transmitting, by the mobile switching center, a second handover request signal including the identification information of the tracking area to the gateway device (HeNB-GW) if a length of the identification information of the second radio base station (eNB#1, HeNB#2, HeNB#3) is a predetermined length and an entry including the identification information of the tracking area included in the first handover request signal is managed by the management unit even when an entry including the identification information of the second radio base station (eNB#1, HeNB#2, HeNB#3) included in the first handover request signal has not been managed by the management unit; and a step of transmitting, by the gateway device (HeNB-GW), a third handover request signal to the second radio base station (HeNB#3) designated by the tracking area included in the received second handover request signal and the identification information of the second radio base station, which corresponds to the identification information of the radio base station.