RFID projects have been deployed in many enterprises profoundly. From the perspective of architecture, a RFID application system includes three parts: hardware, software and middleware. The hardware consists of RFID readers, tags and antennas. Software refers to the enterprise management information system which has been operated for a long time. Middleware is the most time-consuming part. How to import data from RFID reader to management information system? Who is responsible for this task? Whether or not adopt off-the-shelf RFID components? All the above issues should be carefully considered. RFID middleware is system software that collects a large volume of raw data from heterogeneous RFID devices, filters them and summarizes them into meaningful information, delivers this information to applications and makes them interoperate with legacy systems. The implementation of RFID middleware in enterprises can provide flexible configuration. Parameters of related components can be set. And then only the required information is imported to the system. When extra RFID readers are added to the system, there is no need to develop program again. The RFID middleware will take care of all these changes. However, the performance of RFID middleware is not satisfactory. In particular, when Web Service is used to bridge the difference of diversified platforms, the efficiency of data transmission is decreased. A Web Service is a software system identified by a URI, whose public interfaces and bindings are defined and described using XML. Web Services allow access to software components through standard web technologies, regardless of platforms, implementation languages, etc. This technology has impacted RFID-based applications in a profound way. For the mobile client system, Web Services enable the integration of various applications in a distributed environment from the resource-limited terminals. Though its performance optimization poses challenges for researchers. Several methods and strategies have been proposed to improve it. In our paper, we design a Context-Store and apply it to the exchange process of SOAP messages between mobile terminal and server. A SOAP message which includes three sections: SOAP Envelop, SOAP Header and SOAP Body, are separated into 2 groups, one is the static part, and the other is the dynamic part. The main idea of our approach is to store the static part while only transmit the dynamic part through network. Then on the receiver side, we can assemble and obtain the whole message. Source: Radio Frequency Identification Fundamentals and Applications, Bringing Research to Practice, Book edited by: Cristina Turcu, ISBN 978-953-7619-73-2, pp. 278, February 2010, INTECH, Croatia, downloaded from SCIYO.COM