East Asia including China, South Korea, Japan and ten members of ASEAN has experienced dramatic changes during the last two decades. These changes are viewed by mainstream theories of international relations as structural changes such as the end of the Cold War, the collapse of the Soviet Union, the 1994 nuclear crisis in the Korean Peninsula, the 1997 Asian financial crisis and territorial disputes. These developments, to a great extent, have made influence on East Asian international relations. However regional peace and stability have been maintained. So, these so-called structural changes do not play decisive part in the region's international relations
and, regional peace and stability have resulted from regional changes. This makes it necessary to study non-structural factors such as identity, collective identity, interest and shared knowledge in East Asian international relations. These nonstructural factors are also key assumptions of Constructivism in international relations. This article examines how Constructivism interprets the role of non-structural factors in East Asian international relations. In order to do so, the article first reviews Constructivist concepts including identity, collective identity and interest. The article then investigates how these factors influence East Asian international relations. It argues that Constructivism has failed to provide significant explanations to East Asian international relations and put forward some food for further investigations.