One of the events in the contemporary history of Iran is the constitutional revolution, which has had many supporters and opponents, among which Sheikh Fazlullah Nouri is a person who was initially in the front of the supporters of the constitution and then he took a place in the opposition front. In the political thought of Sheikh Fazlullah Nouri, this article deals with each of the components of parliament, freedom, equality and majority vote that were proposed in the constitutional revolution. The findings of the research indicate that the main factor behind Sheikh Fazlullah's opposition to the constitution is his legalistic view of the constitution, and none of the other hypotheses in this field have a position as strong as this opinion. The method of the current research is descriptive-analytical, which has used first-hand historical sources.