Although ASEAN has an impressive record toward a consolidating regional organization, the analysis on the creation of regional nuclear energy governance is rarely examined. The existing scholarship mainly focus on the role and functions of its nuclear weapon-free zone, so-called SEANWFZ. Apart from the emphasis on SEANWFZ, most of academic works consider the relationship between nuclear issue and strategic threats, including non-proliferation and terrorism. While some shed light on the policies and energy demands of a specific ASEAN country. This study takes on exploratory case studies as its main method. Main sources of this research are from academic articles, ASEAN documents, website on the international organizations related to nuclear 3s, and online news. This work will also employ the interviews with the policymakers who are relevant to the political processes led to the establishment of the ASEANTOM. This research found that the ASEANTOM took place based on the three factors: Thailand’s leadership, global and regional norms, and ASEAN member countries’ preferences. It also complements the existing explanation by arguing that ASEAN has been taking a Globalist approach, which refers to ASEAN’s preferences toward global norms on nuclear non-proliferation and energy issues.