Repu: blic and democracy are two terms applied to mean ruling of people since fifth century B.C. They have been especially and tremendously emphasized in west since 16th century. To clarify his ruling system prior and subsequent to the victory of revolution, Imam Khomeini applied these terms as well. What republic and democracy quantitatively and qualitatively mean in Imam Khomeini's political thought is the main inquiry this article tries to answer. It seems Imam Khomeini applied the term republic more than democracy to mean people's pivotal role in the state which is closer to his desired ruling model i.e. welayat-e faqih. Findings of this article indicate that capacities of Islam with necessities of time and place are demonstrated with the term republic more than democracy and that Islamic Republic (religious democracy) is more compatible with the former and less with the latter.