Embodiments of the present invention disclose a public land mobile network PLMN selection method, including: when a mobile terminal is about to hand over from a first cell to a neighboring second cell, selecting, by the mobile terminal, a preferred PLMN after handover to the second cell; and sending, by the mobile terminal, identifier ID information of the preferred PLMN to a base station controller to which the first cell belongs. The embodiments of the present invention further disclose a mobile terminal, a base station controller, and a core network device. By applying the present invention, the PLMN to which the mobile terminal intends to hand over can be determined properly.