The nature of the japanese foreign economic policy has the dual aspect. It was passive in the sense that the private sector mainly took the initiative in pursuing the goal of regional economic cooperation. Also the expansion of japanese economic influence in Southeast Asia was stimulated by the international pressure to appreciate the value of the yen around 1985. However, we can notice the active aspect from the fact that the process of Japanization of the Southeast Asian economy has not been totally left to the invisible hand of the private sector, Instead, it has been orchestrated by the japanese government in one way or another. Furthermore. the nature of economic relations among member countries of the Japan-centered economic sphere is much more hierarchical, though informal, than those in the EU and the NAFTA. This dual aspect reveals the gap between the pattern of Japanese economic behavior and the relative importance of the Japanese economy in the world. The Japanese economic behavior has not yet departed from the neo-mercantilist strategy of the past, while its economy has already acquired the status of the quasi-hegemony has already acquired the status of the quasi-hegemony in the world. The gap has been the most important cause of the structural imbalance of the world economy in recent years. Thus, a major adjustment is necessary in the pattern of Japanese external economic relations, that is, continuing accumulation of current account surplus and the export of accumulated capital through foreign investments. It will e desirable for the Japanese government to actively pursue the goal of productivity increase and the quality of life through increased public investments and stimulated domestic demands.