A method and an apparatus for identifying a UE in an SAE network, and an MME are provided herein. The method includes: receiving an SAE-TMSI which is allocated to a UE that accesses an SAE network and includes at least: a pool-ID, an MME-ID, and a UE temporary identifier; using the SAE-TMSI to temporarily identify the UE in the SAE network. The apparatus includes: a receiving unit and a temporary identifying unit. The MME includes a temporary identifier allocating unit. Moreover, a method for transmitting and allocating a temporary identifier, and a method for receiving and transmitting information according to the temporary identifier are disclosed herein.