After the Cold War, international relationships changed from the Yalta System (emphasis on military alliance and arms race led by both superpowers the U.S. and the former Soviet Union) to the Malta System (emphasis on economic and security cooperation). Multilateral security cooperation mechanisms in the Asia Pacific were established one after another under the transition of the whole international circumstance. For purposes of maintaining regional stability, the PRC fully participates in the following meetings: ASEAN Regional Forum¡BThe Four Party Talks¡BAsia Europe Meeting¡BASEAN+3 Informal Summit¡BASEAN+1 Informal Summit¡BASEAN-China Dialogue Session¡BWorkshop on Managing Potential Conflicts in the South China Sea and Council for Security Cooperation in the Asia Pacific. It is a worthy issue to continuously observe whether these mechanisms can indeed shape China as a regional responsible member. On the other hand, we must question whether the PRC's participation is merely a tool that can help achieve other underlying purposes. Accordingly, this thesis will discuss two main subjects. Firstly, we will look into China¡¦s standpoints and strategies for participating in these Asia Pacific multilateral security mechanisms. Secondly, we will examine the Asia Pacific security strategies of the U.S., JAPAN, and ASEAN as well as their standpoints and strategies towards the PRC's participation in the Asia Pacific multilateral security mechanisms.