The spatial transformation of East Asian international relations, characterized by the emerging cross-border regions, has a close relation to the sea as an exchange and networking space. This paper renders, in terms of 'critical geopolitics', the representation of the dynamics between the continental and the maritime in the evolution of East Asian time-space to illustrate the historical recurrence of 'maritime Asia' as an alternative of 'continental Asia', and to show that such cycles may be related to the unsynchronized developmental trajectories of 'two China', maritime and continental, during the middle and late imperial periods. A political economical conceptualization of 'maritime China' and an exploration of commercial traditions in the 'East Asian Mediterranean Sea' reveal that the historical practices of regional political economy contribute to the subregional and grass-rooted characteristics of contemporary East Asian regional cooperation. Although it is a minor tradition, Maritime Asia, then, is regarded as social assets to be institutionalized by continental Asia to overcome the limits of the latter in the development of East Asian international society.