I. Introduction
The publish/subscribe system realize the decoupling between producers and consumers, so that producers and com-sumers of content messages do not need to understand the specific information of others [1]. According to different subcribe model, the publish/subscribe system can be divided into three categories: channel-based, topic-based and content-based. The former two systems is easy to achieve, but the expression ability is weak, and content-based publish subscribe systems (CBPS), because it is not affected by predefine of system [2], and there is a rich and flexible subscription language, CBPS is gradually becoming the research hotspot. The typical prototype system consists of Elvin, Gryphon, Siena and JEDI etc. [3]