IM is an instant messaging system to send and receive system for IT services based on the Internet protocols and has been expanding rapidly for applications used by individuals and organizations. In this paper, we focus on the design of a server for IM and discuss some technology for IM systems. We then describe a scheme for IM based on XMPP/SIMPLE that supports terminal of SIP to communicate with other IM systems through server and assures remote data file security and efficiency to better communication.