The year 2017 marks the 50th anniversary of the founding of AESAN and the 20th anniversary of the mechanism between AESAN and China，Japan and South Korea. The summit has become an important part of multilateral diplomacy of leaders in East Asia especially in ASEAN. With the acceleration of ASEAN’s integration，Southeast Asian countries have once again become one of the focuses of concern and contention for big powers. Taking the AESAN summits as a stage，leaders from 16 East Asian countries as well as the United States and Russia visit Southeast Asia each year. Japan has taken the summit diplomacy as an approach to show its “special relations” with ASEAN countries. Now the Abe administration has inherited the practice of attaching importance to the diplomatic efforts of the ASEAN Summit，with a strong political intention of building an ambitious diplomatic network targeting China throughout adjusting the foreign strategy，keeping close relations with ASEAN countries and cooperating with U.S..