This thesis is based on the theoretical knowledge derived from the European integration experience to conduct a comparative study between the EU and ASEAN. This thesis investigates how endogenous factors affect how exogenous factors influence the EU and ASEAN institution building process within the European Single Market and ASEAN Free Trade Area. It argues that ASEAN members' domestic political interest and national preference formed within their cultural context as a result of their informal institutional economic cooperation. The thesis reviews literature and finds that the European model cannot be simply applied to ASEAN, thus a combination of new regionalism and liberal intergovernmentalism seeks to contribute alternatives to different aspects in the analysis of ASEAN regional integration.