Serving gateway selection method and mobility management entity

The invention discloses a serving gateway (S-GW) selection method and a mobility management entity (MME). The serving gateway selection method comprises the following steps: when confirming the need to reselect an S-GW for UE (User Equipment), the MME determines a first S-GW candidate list corresponding to a TAI (Tracking Area Identity) of a TA (Tracking Area) to which the UE is attached; the MME determines a first P-GW (Packet Data Network Gateway) candidate list corresponding to an APN (Access Point Name) used by the UE; the MME selects one S-GW which is arranged in a physical device together with P-GWs in the first P-GW candidate list from the determined first S-GW candidate list and takes the selected S-GW as the S-GW reselected for the UE. The technical scheme of the invention provides a specific implementation scheme for the MME to reselect an S-GW for the UE.