This report is the overall report of the “International Seminar on Cultural Diversity of the Mekong River: Sharing Experience from Japan and Mekong Countries” held on November 19-20, 2009 organized by Mekong Sub-region Social Research Center [MSSRC], Faculty of Liberal Arts, Ubon Ratchathani University. The objective of the seminar is to reemphasize and reevaluate the importance of locally cultural and social sensibilities in the Mekong region, as the pace of economic development quickens and the region’s incorporation into the global economy intensifies. This seminar thus aims to bring together assorted stakeholders – selected Japanese and Southeast Asian regional experts, NGOs, and local voices from the Mekong region – to discuss and share perspectives on development, cultural change and adaptation, diversity, and the resilience of local livelihoods. We aim to assert local culture and worldview into the discourse of Mekong development, to explore how local knowledge and social organization could be better integrated in regional development practices, and to reinvigorate efforts to revive Mekong regional identity. The outcomes from the seminar bring to sharing knowledge and let us to thinking of important thing to living together in the Mekong region. Indeed, building networks of academics and activists at the local to global level especially with Japanese is also the important one.