为解决RIA环境下Web离线使用问题，提高Web系统的性能。在分析了独立存储（Isolated Storage）的特点的基础上，本文提出了在Web商务系统中独立存储的应用方案。并运用Isolated Storage APIs，设计实现了本地小型数据库管理组件，解决了本地数据存储问题；提出和实现了增量更新的数据同步工作引擎，该引擎使用TCP Socket通信。通过设计实现Socket服务，实现客户端和服务器的时间同步，并采用推送的方法，将同步数据推送到客户端。实验表明，该系统在低带宽或网络故障状态下运行良好，可提高Web系统的可靠性。

To improve the Web system performance, Web which works under the offline state is studied. Based on the features of Isolated Storage, the solution of using the Isolated Storage in a Web commercial system is presented. A local smallscale database management component is designed with the Isolated Storage APIs, and the management of the local data storage is solved. Meanwhile, the local data synchronized with the remote data is achieved based on the incremental updating of the data synchronization engine, which uses the TCP socket communications. The socket service is designed to achieve the clientserver time synchronization and push data to the client from the server. The experimental results show that, this system runs well in a low bandwidth or network fault state, and the reliability of the Web systems is improved.