East Asia has yet achieved a successful regional cooperation in spite of deepening regional interdependence. However, this study will show that the demand of a regional cooperation in East Asian region grows larger than ever. It is because cooperation and a policy coordination of the countries in the region for common profits becomes more necessary. This article will consider the viewpoint of regional cooperation, change of an attitude of East Asia and policies on cooperation plans. This article reviews previous studies of East Asia regional cooperation which could be categorized into Korean and foreign perspective. I try to clarify the contributions and limitations of previous literature. I also define the main concepts relating to the regional cooperation, such as ; regionalization, regionalism milieu. Finally I have made a comparative study of the cooperation theory; neorealism indicates that a regional cooperation of East Asia is inherently impossible, at best their cooperation which makes less developed countries to be incorporated in the system where the hegemonic power leads. And soft regionalism points out various background which prevents the political cooperation from emerging. This article will consider the possibility and the prospect of East Asian regional cooperation on the basis of neoliberal institutionalism as an alternative approach. Regional interdependence inevitably gives way to the demand of regional cooperation. East Asia should strive for regional cooperation through stat-led pattern beyond bygone.