A communication system and a communication method

The invention discloses a communication method and a communication system which are used for making a client timely know a long connection establishment situation and communicate with a server. The communication system comprises the client and the server, wherein the server comprises a storage unit, a communication interface and a communication controller, wherein the communication controller is used for judging whether a client information list stores a long connection channel identifier corresponding to a client identifier; if the long connection channel identifier is stored, the communication controller controls the communication interface to return a first response message for indicating that long connection is established to the client; if the long connection channel identifier is not stored, the communication controller distributes a long connection channel to the client; the long connection channel identifier of the long connection channel and the client identifier are stored into the client information list, and the communication interface is controlled to return a second response message for indicating that the long connection is not established to the client; and the communication interface also transmits message between the server and the client according to the long connection between the communication interface and the client.