Since Shinzo Abe took office as Prime Minister of Japan for the second time in 2012, he has vigorously promoted the value-based diplomatic strategy of the "Arc of Freedom and Prosperity", of which Southeast Asia is an important part of this diplomatic strategy that cannot be ignored. Among them, Official Development Assistance (ODA) is an important diplomatic tool in Japan's diplomatic strategy for Southeast Asia. On the other hand, Japan has continued to develop bilateral relations with Vietnam since the end of the Cold War, and Vietnam has also played an important role in Japan's Southeast Asian diplomatic strategy. This study will sort out the history of Japan's past foreign ODA, Japan-Vietnam relations, and the diplomatic strategy of the Abe Cabinet, and observe the significance of Japan's representation of ODA in Southeast Asia in this diplomatic strategy from the perspective of ODA in Vietnam. Keywords: Japanese foreign relations, Japan-Vietnam relations, Official Development Assistance