The 4th Japan-Japan Strategic Dialogue was held by Institute of International Affairs in at the Tokyo, Japan. Starting from May 18 to 19 ,2017. Continuing the "two-track dialogue"(Track II Dialogue) way, Taiwan-Japan think tank aims to promote discussion and cooperation on national security, diplomatic and strategic issues. This year, Taiwanese Participants mainly are members from the Taiwan Society of Japan Studies, Institute of National Policy Research, Taiwan Democratic Foundation, etc., Japanese participants are mainly from the Japan Institute of International Studies, University of Tokyo and other units. This time, there are five theme panel in the 4th Taiwan-Japan Strategic Dialogue, titled "Japan-Taiwan Relations", "Cross-strait Relations", "Domestic Situation in Mainland China", "US Foreign Policy"and "Principle of International Cooperation in Flux". In the Dialogue, participants discussed the policy including: (1) the United States President Chuopu's foreign policy (2) the Korean Peninsula missile crisis (3) the institutionalization of Taiwan-Japan relations (4) the stalemate of cross-strait relations (5) the regional economic integration trend (6) the strategic arrangement between the United States and China (7) the dispute over the East China Sea and the South China Sea, etc. It is the goal to promote further development of diplomatic and security policy.