Service Oriented EXtensible Modeling and Simulation Supporting Environment Architecture (SO-XMSSEA) is presented based on XMSF thinking and the new technology development of web service and grid. Simulation Service Bus (SSB) is the underlying infrastructure to take charge of services communicating in SO-XMSSEA including message dispatch, integration, services interaction, management with services quality and security, and adaptation with other domain applications. We introduce the main mechanism of SSB structure and survey the communication and data transferring between clients and server. As the most important approach for composing HLA systems, the core module of SO-RTI Server and System Integration Server are discussed in detail. WSRF based grid technology is selected to construct prototype SSB implementation. A test HLA system based on SSB shows the interoperability on heterogeneous systems so that different types of systems can communicate smoothly through WAN and makes more faci...