The present study is aimed at studying the experience of forming a regional security architecture on the example of Southeast Asia.Aim. Study and generalization of the historical experience of the formation of the security architecture in Southeast Asia and its current state, participation in a scientific discussion on the problems of the Eurasian space.Tasks. To carry out an express analysis of the fundamental decisions of the Association of Southeast Asian Nations (hereinafter — ASEAN, the Association) on security issues, their effectiveness in regional political practice; to identify the main problems of the process of forming a regional security system and the impact of global instability, contradictory bilateral relations between the states of the region; to determine the reasons for the eclecticism of its current state, as well as different approaches to assessing the results of ASEAN’s activities over the entire period of its existence, caused by the lag in making operational decisions on security in the conditions of real modern socio-political and economic processes; to identify the main mechanisms and tools of the Southeast regional security architecture from the East Asian Summit to the Committees ASEAN by areas of activity, from Joint Statements to Programs, including the ASEAN Regional Security Architecture Program, and Action Plans.Methodology. Using historical, comparative and structural-functional methods based on the main content of the documents of the ASEAN Regional Forum, the East Asian Summit, the Russia-ASEAN dialogue program, as well as research models of Russian and foreign scientists and experts, existing problems were identified, the process of forming a regional security system, and the need to study the experience of ASEAN was justified.Results. The study showed the general and special features of the process of formation of the regional security system of Southeast Asia and regional security architectures in Central Asia and Europe. It is confirmed that the current global uncertainty and instability contribute to the formation of a trend towards regional coalitions and the strengthening of regional security architectures. The multidirectional positions of the members of the Association on issues of national and regional security have been revealed. ASEAN uses the experience of other regional coalitions, primarily NATO, in shaping the security architecture. There are problems in the efficiency of decision-making and this has both negative and positive consequences.Conclusions. In contrast to the established Euro-Atlantic security architecture, which excludes a significant part of Europe in the form of the European part of the Russian Federation, the Eurasian strategic space is currently in the process of forming a security system, which includes only certain groups of states. The research is mainly aimed at studying approaches to the content and forms of cooperation between these countries in security issues. Modern global processes negatively affect all levels of security and actualize the problem of strengthening it at the regional level. Even in the difficult conditions of Southeast Asia, ASEAN manages to partially minimize the consequences of challenges, threats and security risks. In the south-eastern strategic region, the problems of protracted conflicts, significant differences in the economic and political development of the member States of the Association still remain unresolved, and this negatively affects the achievement of unity and the development of cooperation relations between the countries of the region, as well as the stabilization of the regional situation. The existing problems in the efficiency of decision-making at the regional level have both negative and positive consequences. They are currently balanced. Participation in the work of various international institutions is of great political importance, and has an impact on the status of subjects of the global or regional political process. Participation in the dialogue programs of the ASEAN of Russia is justified and contributes to the continuation of contacts with the countries of Southeast Asia. The experience of the long-term existence of the regional coalition can be used in other regions of Eurasia.