After the end of the Cold War，the United Nations peace operations have experienced a transformation from “peacekeeping” to “peacebuilding”. Peacebuilding aims to reduce the risk of lapsing or relapsing into conflict by strengthening national capacities at all levels for conflict management，and to lay the foundation for sustainable peace and development. Australia has been actively involved in peacekeeping and peacebuilding operations，and provides support for UN to improve the concept and architecture of peacebuilding. There are four driving forces for Australia to involve in peace operations：maintaining its own security and the stability of its surrounding regions，consolidating its leading position in the Pacific Islands region，strengthening its alliance with the United States and increasing its global influence. Australia’s three major foreign policy traditions—the Spender-Casey tradition in attachments to regional affairs，the Menzies tradition in support of the alliance and the Evatt tradition in inclination of global or multilateral frameworks—have a substantive impact on the region，approach and agenda of its engagement in peace operations.