The article deals with the study of the interaction between eight South American countries (Brazil, Bolivia, Venezuela, Guyana, Colombia, Peru, Suriname and Ecuador) in the frame of the Amazon Cooperation Treaty Organization (ACTO). The study of ACTO’s activity is becoming a particular relevance currently, when the integration processes in Latin America are going through crisis and it’s difficult to predict the prospects of regional dialogue, including the environmental component, connected with the social and economic factors. Considering this research, the authors drew on the theory of regional integration, the neoliberal IR theory and used the problematic-chronological method in considering the program documents and projects of ACTO. © 2021, Rossiiskaya Akademiya Nauk, Institut Istorii (Russian Academy of Sciences, Institute of General Hist. All rights reserved.