International relations as a discipline that studies the interactions between and among statesrnhave gripped the attention of many scholars. These scholars have derived different theories andrnprinciples that are presumed to result in smoother and cooperative relations between andrnamong states. Despite the development of diverse theories and principles of internationalrnrelations, contacts between and among states have not been as contemplated by those goodrnwishing scholars. In this regard, the coherent nature of international relations- cooperation andrnconflict-have persistently continued. Plus, these features of international relations are stillrngoverning the trends of relations between states.rnEthio-US relation is not an exception in this regard. The century old relations between Ethiopiarnand the United States have so far been traversing through these controversial features- conflictrnand cooperation. The cooperative features of the Ethio-US relations have contributed to thernbuildup and the continuity of the cordial relations. On the other hand, the conflictingrncharacteristic of the relations between the two countries have brought in changes in thernmanner of the relations from a friendly type to an unfriendly mode, or have contributed to the shaping of unpleasant and hostile relations.rnThis essay endeavors to identify the factors that have contributed to the continuity of thernfriendly relations between the United States and Ethiopia. On the other hand, the factors thatrnhave resulted in changes in the gracious relations between the two countries have also beenrnscrutinized.rnThe methodology applied to gather the data is a qualitative one. This method is put in usernbecause; the data used in conducting the research is totally related to words observations, andrnthe approach has been analyzing and interpreting the data. By examining, analyzing andrninterpreting the data the thesis has identified the factors of Ethio-US security relations.rnAccordingly, the Kagnew Communication Base, the secessionist group in Eritrea, the Republic of Somalia before and after its disintegration, the Cold War phenomena, the end of the Cold War and the disintegration of the Soviet Union, the geo-political position of Ethiopia, and the international political system have been identified as the major ones. These factors of relations have played different roles in shaping the relations to continue either in a friendly fashion or to change the mode of the relations