Border region is an important national security barrier and opening gateway. In the context of globalization and rapid development of information technology, research on border region has become a hot topic of geography, political science, and political economy internationally. In this article, by means of bibliometric measurement of the Citespace tool and using data from the Web of Science in 1990-2015, international frontiers and trends of border research have been reviewed systematically. The results of bibliometric statistical analysis show that, since 1990, most of the articles on border research were published in political geography and geopolitics journals. The fields of international border research include political geography, environment, ecology, business, economics, public administration, culture, among others. Geopolitical territory and state power have always been important parts of the border research frontier. Since the 21st century, critical geopolitics and humanism geopolitics have been applied to border research, including rethinking societal governance and other aspects of border areas. This article also reviews the key research trends, including economic and trade exchanges, border integration, border conflicts and security, cultural and social construction, as well as cross-border cooperation systems. Finally, it recommends that Chinese border research in the future should emphasize comprehensive strategic research of border areas; build cross-border cooperation platforms and mechanism; and integrate the international political science, ethnology, physical geography, and other multi-disciplinary approaches.