It is mainly Open IMS Core in the software implementation of platform for the IMS core network currently. Though most of the existing IMS clients have their own specialty, they poorly communicate between each other. The client-side components of Doubango are based on the unified framework of Doubango, wireless clients and fixed clients of which possess the same algorithm of exchange information and have good interoperability. This paper describes current main IMS clients of open source and carries out interoperability tests, then analyses the software architecture of Doubango’s client-side components, finally add a new function to one of components. The client architectures presented in this paper can be important foundation of extending the IMS clients, making which take high-performance applications on, and can be applied in different operation system to expand the serviceable range of IMS clients.