Peer-to-peer conference is an interactive multi-users conferencing application that improves the issues of concentrated loading, single-point failure and expensive infrastructure cost for the traditional centralized conference model, according to the conference resource shared by each other. The benefit of non-centralized system can be achieved by using P2P-SIP. However, unlike the traditional centralized architecture, the conference resource is provided by each peer user. How to search the heterogeneous resource efficiently is a key point in the dynamic and distributed environment. Thus, we proposed a multi-constraint resource search algorithm for P2P-SIP conferencing services. In the full distributed environment, users can search a usable resource to reduce the call-setup time and save the conferencing cost according to the conferencing scale and the quality requirements.