http://cogprints.org/3795/ Power Law Signature in Indonesian Population The paper analyzes the spreading of population in Indonesia. The spreading of population in Indonesia is clustered in two regional terms, i.e.: kabupaten and kotamadya. It is interestingly found that the rank in all kabupaten respect to the population does not have fat tail properties, while in the other hand; there exists power-law signature in kotamadya. We analyzed that this fact could be caused by the equal or similar infrastructural development in all regions; nevertheless, we also note that the first 20 kabupatens are dominated in Java and Sumatera. Furthermore, the fat tail character in the rank of kotamadya could be caused by the big gap between big cities one another, e.g.: Jakarta, Surabaya, and others. The paper ends with some suggestions of more attention to infrastructural development in eastern regional cities. Mulianta, Mr Ivan Situngkir, Mr Hokky Surya, Prof Yohanes Statistical Models Economics Social Psychology Ivan Mulianta Hokky Situngkir Yohanes Surya