Association of Southeast Asia Nations (ASEAN) was established as the regional organization. During the very first establishment of this organization, ASEAN focused on the political stability and security. However, the cooperation develops to the economic cooperation. This regional organization develops to integrate the economic cooperation among the member states. The benefits from the deepening integration of economic cooperation should be shared equally among the member of ASEAN. However, along the establishment of the integration, the economic disparities become one of the obstacles for ASEAN’s economic cooperation. Economic disparities define as the condition of being unequal. It will lead to the different implementation on the further integration and the stagnancy of growth. Thus, narrowing the economic disparities becomes one of the concerns for ASEAN. This undergraduate thesis describes the roles of ASEAN in narrowing economic disparities among ASEAN Member States. The research particularly focuses on 2000-2009, after the ASEAN established the framework of Declaration on Narrowing Development Gap (2000) and the Initiative for ASEAN Integration (2002).