A method for notifying gateway update information applied to an Evolved Packet System, EPS/General Packet Radio Service, GPRS, network implemented by a Software Defined Network, SDN, characterized in that, the method comprises: reselecting (S301, S401, S501, S601, S701, S801, S901, S1001, S1101), by a controller, a gateway to obtain a new gateway; sending(S303, S404, S502, S602, S702, S802, S902, S1002, S1102), by the controller, user plane information of the new gateway to a corresponding front-end network element, wherein the user plane information comprises user plane address information of the new gateway; wherein sending, by the controller, the user plane information of the new gateway to the corresponding front-end network element comprises: sending a GPRS Tunnel Protocol, GTP, notification message or GTP Update Bearer Request message carrying the user plane information of the new gateway to the front-end network element; or sending a GTP Update Bearer Request message carrying an update indication to the front-end network element, sending, by the front-end network element, a GTP Modify Bearer Request message to the controller according to the update indication, and sending, by the controller, a bearer response message carrying the user plane information of the new gateway to the front-end network element through a GTP Modify Bearer Response; wherein the gateway, the controller and the front-end network element, are comprised in the EPS/GPRS network implemented by the SDN; and wherein the front-end network element is a mobility management entity or a Serving GPRS Support Node, SGSN, supporting S4 interface. reselecting (S301, S401, S501, S601, S701, S801, S901, S1001, S1101), by a controller, a gateway to obtain a new gateway; sending(S303, S404, S502, S602, S702, S802, S902, S1002, S1102), by the controller, user plane information of the new gateway to a corresponding front-end network element, wherein the user plane information comprises user plane address information of the new gateway; wherein sending, by the controller, the user plane information of the new gateway to the corresponding front-end network element comprises: sending a GPRS Tunnel Protocol, GTP, notification message or GTP Update Bearer Request message carrying the user plane information of the new gateway to the front-end network element; or sending a GTP Update Bearer Request message carrying an update indication to the front-end network element, sending, by the front-end network element, a GTP Modify Bearer Request message to the controller according to the update indication, and sending, by the controller, a bearer response message carrying the user plane information of the new gateway to the front-end network element through a GTP Modify Bearer Response; wherein the gateway, the controller and the front-end network element, are comprised in the EPS/GPRS network implemented by the SDN; and wherein the front-end network element is a mobility management entity or a Serving GPRS Support Node, SGSN, supporting S4 interface. sending a GPRS Tunnel Protocol, GTP, notification message or GTP Update Bearer Request message carrying the user plane information of the new gateway to the front-end network element; or sending a GTP Update Bearer Request message carrying an update indication to the front-end network element, sending, by the front-end network element, a GTP Modify Bearer Request message to the controller according to the update indication, and sending, by the controller, a bearer response message carrying the user plane information of the new gateway to the front-end network element through a GTP Modify Bearer Response; wherein the gateway, the controller and the front-end network element, are comprised in the EPS/GPRS network implemented by the SDN; and wherein the front-end network element is a mobility management entity or a Serving GPRS Support Node, SGSN, supporting S4 interface.