This invention can avoid unnecessary signal transmissions and shorten a time in which to establish a bearer to be used for UE. A mobile communication method of the present embodiment comprises: a step in which a P-CSCF, when having received a SIP signal #1, notifies a PCRF of a QoS corresponding to an SDP-A included in the SIP signal #1; a step in which the PCRF transmits a bearer setting instruction signal #1 to an EPC on the basis of the QoS; and a step in which the P-CSCF, when having received a SIP signal #2, does not notify the PCRF of a QoS corresponding to an SDP-B included in the SIP signal #2 when the SDP-B is identical with the SPD-A included in the SIP signal #1.