Iranians became familiar with modern concepts from the beginning of the Iranians' visits to the Western world. Among them, the three concepts of "state", "law" and "constitution" have been of great importance in the intellectual system of the intellectuals of the Qajar era. The objectification of the mental form of the "orderly" structures of the political-legal order has later found its place in the Iranian constitutional movement. Taghizadeh is among the intellectuals who are the pioneers of this emerging field of Iranian modernism. In the present study, we will answer the question of what aspects the rule of law and the constitution have in the thought of Seyyed Hassan Taghizadeh? In this regard, we have used primary sources such as the collection of books "Taghizadeh's Essays" (especially volumes eight to ten of this collection, which include Taghizadeh's speeches in the first to fifteenth periods of the National Consultative Assembly in his role as a member of the parliament, Minister of Roads and Streets, Minister of Finance, and also the President of the Senate). The results of this study show that Taghizadeh's perception of concepts such as law and constitution was not uniform throughout his political life. In the present study, we have used the framework of Quentin Skinner's coherence theory, benefiting from the opinions of Taghizadeh's commentators, and in terms of methodology, we have used a qualitative and descriptive-analytical method using library and Internet tools.