The administrative decentralization system is one of the most important systems that help the state to maintain its unity, especially in democratic countries, as it is one of the most important pillars for the success of the democratic process in the state, especially in countries that are transforming from a centralized dictatorial system to a decentralized democratic system. 2005 and currently in force, and as a result, many laws were issued in implementation of what was included in the constitution in Iraq to draw the legal system of administrative decentralization in it, including the main features of evaluating this system, and this will be the goal of our research, shedding light on the concept of administrative decentralization and its pillars and elements.