Abstract: Entering the 21st century, Japans infrastructure diplomacy towards Southeast Asia is becoming increasingly active. Revitalizing the economy through infrastructure exports is the internal cause of Japans infrastructure diplomacy towards Southeast Asia, while countering Chinas ‘the Belt and Road” initiative is the external cause of Japans infrastructure diplomacy towards Southeast Asia. Consolidating Japans dominant position in Southeast Asia through infrastructure exports is a strategic consideration of Japans infrastructure diplomacy towards Southeast Asia. The Democratic Party government and the Liberal Democratic Party government have successively formulated strategies and policies to promote the export of overseas infrastructure, using various policy tools, establishing a government civilian cooperation system, focusing on the Mekong region, and cooperating with the United States, Australia, and India, which have become important strategies for Japans infrastructure diplomacy towards Southeast Asia.

Key words: Japan, Southeast Asia, infrastructure diplomacy