The present research project is derived from a research to the state-building model in Islamic Republic of Iran, using the historical-institutional approach to state-building. According to this approach, the complex and extensive process of state-building has to be studied regarding four aspects: 1. External or internal origin of state-building, 2. Instruments and resources (physical or unphysical) in this process, 3. Main forces (pro or for) participating in the process, and 4. The major factors required for building state, which in turn consists of four elements of establishing order, bureaucracy, institutionalism, and developmentalism. The research does not ignore the background of state-building in the history of Iran. We have discussed this in second chapter of the research. Historically speaking, Islamic Revolution can be considered as the result of the failed state-building project in the period of Pahlavi II. According to historical-institutional approach, revolution acted as a “momentous event” in this process where revolutionary elites caused extensive institutional changes in the four areas of state-building, using a traditional ideology to evoke masses, relying on oil incomes and the specific circumstances inside and outside the country, particularly after the Revolution. In chapter three, it is discussed that Iran’s model of state-building was developed during the first three years after the Revolution. Then in chapter four, we show that this model continued to exist with slight modifications for three decades. Successions and changes in state-building models from the Safavid dynasty up to the present were studied in chapter five. Findings of the research show that state-building process in terms of its origin has been a sinusoidal movement during this period of time. The Safavid’s use of Shiism, and Persian Language to establish political solidarity and order is considered as an important milestone in state-building process in Iran, regarding to making use of unphysical resources. In the states after the Safavid, this model continued to be dominant, with the occasions of severity or weakness, and served as a factor of succession and contiuity in this process. Once the oil incomes were introduced to the country’s budget, it caused major shif in physical resources of state-building process. Prior to oil incomes, taxing villagers by government, and domestic and foreign trades were main source of state budget in Iran. As for human forces of state-building, fading out the function of tribe celebrities in the structure of state since the Pahlavi dynasty is indicative of formation of a different structure known as unitary state opposed to segmentary state. Various patterns of succession and change in the structure of state have been also seen from the Satavid to the post-Revolution state.