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 .