Abstract: This dissertation is a study of Japanese perceptions of its East Asian neighbors - China and Korea - and the making of foreign policy from the early seventeenth century to the late nineteenth century. Previous studies have overwhelmingly argued that after the Meiji Restoration of 1868, Japan started to modernize itself by learning from the West and changed its attitudes toward those neighboring countries. It supposedly abandoned its traditional friendship and reverence toward its neighbors and adopted aggressive and contemptuous attitudes. I have no intention of arguing here that the perspective of change and discontinuity in Japan's attitudes toward its neighbors has no validity at all; Japan did adopt Western-style diplomacy toward its neighbors, paralleling the abandonment of traditional culture which had owed much to other East Asian civilizations since antiquity. In this dissertation, through examination primarily of official and private documents, I maintain that change and discontinuity cannot fully explain the Japanese policy toward its East Asian neighbors from the early seventeenth to the late nineteenth century. The Japanese perceptions and attitudes toward China and Korea had some aspects of continuity. I also challenge previous studies' argument about the change in Japanese attitudes toward China. Although they have argued that Japan turned aggressive soon after the Meiji Restoration. I contend that that kind of change did not occur at the time. Chapter 2 focuses on the Tokugawa perceptions of and diplomatic relations with Korea. Chapter 3, focusing on Tokugawa China policy, examines the Tokugawa vision of the Chinese tributary system and policy toward China. China's status was ambiguous in the hierarchical Tokugawa international relations, though the Tokugawa perception of China was under the sway of ideological and religious belief in Japanese superiority. Chapter 4 focuses on the attempt of the Meiji government to establish a government-to-government relationship with Korea. Chapter 5 deals with two issues of the early Meiji Japanese policy toward China.