Method, apparatus and system for notifying network releasing resource

The embodiment of the invention relates to the field of communication and provides a method, a device and a system which are used for informing a network to release resource. The IP address of the opposite network element is obtained through the instruction information; the mobile management network element of the opposite network is informed to release resource according to the IP address or the opposite element is informed to release resource through message interaction; and the invention correspondingly provides the device and system which release resource through the network, thus solving the problem that the opposite mobile management network element cannot be informed to release resource if the opposite mobile management network element cannot be searched.