In this study, the author tries to discuss and uncover the thoughts of Ayatollah Khomeini about the concept of Wilayatul Faqih, the application of Wilayatul Faqih in modern Shia, and analyzes the position of Faqih in the constitutional system of the Islamic Republic of Iran according to the perspective of siyasa fiqh. In writing this article, the author uses a research approach in the form of library research, namely by researching books related to the discussion, both primary and secondary books, which are useful for formulating more accurate data in concluding the answer to this research. This study has the result that the government referred to by Imam Khomeini is a government that is not tyrannical, or a concept of government that is under the clergy, the highest authority of the state is under the hands of scholars or, more specifically, is a rahbar. Imam Khomeini's goal in the Wilayatul Faqih concept is to demand social justice, a fair distribution of wealth, a productive economy based on national strength and a simple lifestyle and based on a conception that will reduce the gap between rich and poor and between government and governed according to the principles of Islam.