In order to enable users to get instant messages with mobile phone equipments at any time and any place, a new platform of XMPP-based SMS gateway was put forward. The designation and implementation of XMPP-based SMS gateway were introduced in detail. A further deep analysis on the format of XMPP message was made to make sure the rationality of the extension of XML. Meanwhile, controlling of GSM modem was achieved through the application of AT commands. A novel XML structure was designed based on the expansibility of XMPP to represent the SMS message. Next, definition of the signaling and construction of the logic structure of XMPP system were made to accomplish the architecture of SMS gateway. A new module of SMS gateway was founded in XMPP server and enabled the realization of interconnection of mobile phone short message and instant message.