Abstract: After the World War Two, the United States helped South Korea found its state. And it took the latter into the American geostrategic system of Northeast Asia in the Korean War and allied with this country. Afterward, because of weak national power, the Korean-American relationship has developed with the United States as a dominator and Korea as a dependent in politics, economy or in military. Since the 1990s, with the end of the Cold War and gradual promotion of Korean national power, the Korean-American relationship has got new features. And Korea has gradually begun its independent political and diplomatic activities. And in the field of economy and trade, it has witnessed the conflict with the United States. And this has brought about the unharmonious factors for the relationships between the two countries which has sowed the seeds for the future development of such relationships.