The present invention relates to a wireless communication system and a connection method between user equipment and a mobility management entity and comprises: selecting a mobility management entity and requesting identification information for user equipment by a base station when the user equipment is connected; determining whether to assign identification information by the mobility management entity; and if the identification information is not assigned, selecting another mobility management entity by the mobility management entity, assigning identification information to the user equipment by the other mobility management entity, and performing a connection with the other mobility management entity by the user equipment. According to the present invention, user equipment can be efficiently connected with a mobility management entity in a wireless communication system.