IMS-based streaming media systems are used in C/S architecture. When numerous users request service simultaneously, the center streaming media server will become the bottleneck of system performance. After referring to ETSI TISPAN IMS-based IPTV architecture, we proposed an IMS manage P2P streaming system architecture, and designed an application server software module structure and P2P distribution tree construction algorithm according to the requirement of introduction P2P. Based on the original C/S architecture streaming application server, we implemented the selection upload node function by extending the centralized management and maintenance of trees P2P module, and verified prototype system in broadcast service. The test result shows that the streaming system can organize UE into P2P streaming media network effectively, and reduce the pressure of the media server and improve system performance.