A method for instant messaging based on a user interface, comprising: providing, in the user interface, a window having a plurality of regions, wherein the plurality of regions comprise at least a navigation region and a message region; navigating among dialog windows displayed in the message region and navigating to switch among the dialog windows, by the navigation region; and displaying the dialog windows in the message region, characterized in that the navigating among dialog windows displayed in the message region comprises: concurrently providing a plurality of pieces of dialog window navigation information corresponding to window identifiers, wherein the plurality of pieces of dialog window navigation information are provided as a stack in an order of user access, wherein Last-In-First-Out data management is used in the stack to return to a previous dialog window when a current dialog window is exited, and in that the method further comprises: providing a message routing function in a logic layer of a client, receiving a message from a protocol layer of the client, and routing, based on a destination window identifier of the received message, the message to a corresponding dialog window of an interface layer of the client or to a message link, wherein the message link is configured to receive a notification of an unread message and the message as corresponding unread message; and transferring the message received from the dialog window of the interface layer of the client to the protocol layer of the client, and sending the message out. providing, in the user interface, a window having a plurality of regions, wherein the plurality of regions comprise at least a navigation region and a message region; navigating among dialog windows displayed in the message region and navigating to switch among the dialog windows, by the navigation region; and displaying the dialog windows in the message region, characterized in that the navigating among dialog windows displayed in the message region comprises: concurrently providing a plurality of pieces of dialog window navigation information corresponding to window identifiers, wherein the plurality of pieces of dialog window navigation information are provided as a stack in an order of user access, wherein Last-In-First-Out data management is used in the stack to return to a previous dialog window when a current dialog window is exited, and in that the method further comprises: providing a message routing function in a logic layer of a client, receiving a message from a protocol layer of the client, and routing, based on a destination window identifier of the received message, the message to a corresponding dialog window of an interface layer of the client or to a message link, wherein the message link is configured to receive a notification of an unread message and the message as corresponding unread message; and transferring the message received from the dialog window of the interface layer of the client to the protocol layer of the client, and sending the message out. concurrently providing a plurality of pieces of dialog window navigation information corresponding to window identifiers, wherein the plurality of pieces of dialog window navigation information are provided as a stack in an order of user access, wherein Last-In-First-Out data management is used in the stack to return to a previous dialog window when a current dialog window is exited, and in that the method further comprises: providing a message routing function in a logic layer of a client, receiving a message from a protocol layer of the client, and routing, based on a destination window identifier of the received message, the message to a corresponding dialog window of an interface layer of the client or to a message link, wherein the message link is configured to receive a notification of an unread message and the message as corresponding unread message; and transferring the message received from the dialog window of the interface layer of the client to the protocol layer of the client, and sending the message out. providing a message routing function in a logic layer of a client, receiving a message from a protocol layer of the client, and routing, based on a destination window identifier of the received message, the message to a corresponding dialog window of an interface layer of the client or to a message link, wherein the message link is configured to receive a notification of an unread message and the message as corresponding unread message; and transferring the message received from the dialog window of the interface layer of the client to the protocol layer of the client, and sending the message out.