Abstract: This study aims at analyzing spatial physic interaction, economy and social in Ternate, Tidore Archipelago and Sofifi City. The spatial interaction occurs through complementary process, transferability and intervening opportunities. This process then developed into city activities system formation. This study applied quantitative approach and qualitative approach (mixed approach). The data collected through obsevation, survey and documentation. The accumulation of the city activity functions which dominantly developed in Ternate City and the available transportation means and infrastructure make Ternate City as the primer service center, Tidore Archipelago City as the secondary service center and the Sofifi Archipelago City as tertiary service center. The physic, economic and social spatial interaction is dominantly developed in Ternate City. This process is mutual induction and show intercity and inter-area service disparity in a unity of city area expansion system in North Maluku Province.