Vietnam served as the rotating presidency of ASEAN in 2020，having played a coordinating role within ASEAN and between ASEAN and relevant countries in the region. Vietnam has become a model for the latecomer countries in Southeast Asia because of its advantages in systems，important strategic position and potential of demographic dividend. The new Japanese Prime Minister Yoshihide Suga，who took office in September 2020，set Vietnam as his first diplomatic destination，making it clearer that Japan has attached importance to diplomacy with Vietnam and exerted influence on ASEAN through key countries since Abe’s second cabinet took office. Vietnam also attempts to attract more Japanese capital and technology to develop its economy and welcome Japan to play a balancing role in Southeast Asia，intending to make use of Japan’s involvement in Southeast Asia in the economic，political and security fields to counterbalance China’s growing regional influence. However，the calculation and transaction involving Japan and Vietnam will not hinder the further deepening of economic ties between China and ASEAN countries after the signing of RCEP，with the general trend of bilateral or multilateral cooperation including China-Japan，Japan-Vietnam and China-Vietnam remaining as the mainstream.