The purpose of this study is to investigate and compare the intellectual structure of cardiovascular research area in Korea and the United States. For the purpose of this study, a data set was collected; one journal Korean Circulation Journal is in Korea and two journals Circulation, and Circulation Research are in the United States. Based on the frequency of citation counts, 45 authors and 53 authors were selected for author co-citation analysis. By multidimensional scaling, clustering, and factor analyses, the results demonstrate that researchers in both countries commonly tend to work on several, rather than focus on certain sub-areas. In both countries, the core areas are revealed as ‘cardiovascular disease treatment’, ‘cardiovascular disease diagnose’, ‘cardiovascular disease fundamentals’, and ‘cardiovascular disease preventives’. One of distinctive differences between two is that research in Korea is likely to focus on clinical medicines while research in the United States tends to be on fundamental medicines. While the area of ‘Disorders of Rhythm’ is revealed in Korea, ‘Pharmacology of the Cardiovascular System’ area is found in the United States. In addition, the sub-areas of fundamental medicines such as ‘Epidemiology of Cardiovascular Disease’, ‘Biology’, ‘Biochemistry’, ‘Physiology’ are revealed distinctively in the United States.