This paper will deal with Japan’s relations with East Asia, especially for China, the Korean Peninsula and Southeast Asia. How Japan view East Asia will discussed firstly. Each section begins by reiterating the factors and how these factors interacted with each other to affect at certain critical junctures the development to Japan’s political relations with the East Asia region. Furthermore, this paper hold Robert Cooper’s view, that is Japan as a kind of postmodern state, but it need use between post-modernism and modernism, even pre-modernism approach to deal with East Asian neighbor countries relations.