Unitary state as provided for in Article l (l) injunction with Article i8 of the 1945 Indonesia?s Constitution, as amended in year 2000 in junction with Law No. 32/2004, falls into an decentralized unitary state model with a federalistic sub-model. In dealing with the problem, a research on the actualization of unitary state after the amendment of Article 18 of the 19-I5 Indonesia's Constitution was carried out. Research used methods of juridical-normative, juridical-historical, and juridical-comparative. The results obtained were as follows. First, notional territory is organized into provincial and local/municipal territories. Second, authority relationships between central government and local government and among local governments are in form of coordination, guidance, and supervision in administrative and territorial aspects. Third term of "territories extraordinary in nature" as provided for in Article 18 of the 1945 Indonesia`s Constitution is originally intended as Swapraja and Village. Based on proportionality principle as upheld by Law No. 32/2004. indonesia should pursue a proportional, decentralized unitary state, with a focus of local autonomy on district/municipal. In order to deal with the problem. under constitutional power, Law on Local Government should be invoked in actualizing a unitary state in implementing local governance.