The main objective of this study is to propose an internet telephone interception system under PcP SIP structure and to investigate VoIP interception mechanism under PcP SIP, DHT and the conventional centralized SIP structure. The stabilization operation in Chord is utilized to acquire the Resource Key of the intercepted target and to play the role of man-in-the-middle to achieve online connection and VoIP interception. We implement the proposed interception system in PcP SIP environment to show the feasibility.