The study of this present dissertation begins with a brief study of the foreign policy of all States of the United States to Latin America and then stresses study of the two recent administration, the administration of Barack Obama and Donald Trump. The policy of the United States and, consequently, administrations in relation to Latin America is diverse and includes various aspects and components. On this basis, both the Obama administration has been elected the Democratic agent and the Trump administration as the Republican agent, each of which has taken special and unique steps in the field of foreign policy toward Latin America. Main questions about the foreign policy of Obama and Trump are to be addressed, and the differences and similarities between the two administrations will be examined in the form of theoretical approaches equal to the agent-structure theory, and decision-making theory. The main question is how the United States foreign policy toward Latin America has been in the administrations of Obama and Trump? The main hypothesis of the research is that the foreign policy of the United States in Latin America during the Obama era, according to the Democratic, hemispherical approach, based on soft and peaceful behavior, and during the Trump era due to the anti- hemispherical approach of the Republicans, was hard and militant. Regarding the objectives of the dissertation, it should be noted that the nature of the field of study of regional cognition is studied, so this dissertation focuses on the inherent nature of the field of American studies and is based on existing regional realities. The research method is upon comparative politics and even in the form of combined-comparative method. The research organization has been made up of five chapters and a conclusion, and the study on the foreign policy of the Obama and Trump administrations will focus on the Obama administration's change strategy and immigration, and the construction of the boundary wall and other important issues in the field.https://lib1.ut.ac.ir:8443/faces/search/bibliographic/biblioFullView.jspx?_afPfm=-gs2s90q62