The embodiments of the present invention provide a method, an apparatus and a system for service establishment for a multi-mode user equipment. In an embodiments of the present invention, a centralized control entity (Controller) may obtain the base station information of the respective base stations in the multi-RAT network in real time and select proper RAT base station information in accordance with service demand of the user equipment, so as to initiate bearer establishment for the service. Compared with the prior art which only aims at a particular service and handover can only be performed in particular RAT networks, the present solution does not has particular limitation on a service, and moreover, a proper RAT network may be selected from multiple RAT networks more flexibly for each service without increasing power consumption of the user equipment.