The "Saint Moritz Agreement" or "Oil Sale and Purchase Agreement" in 1973 created a new development in Iran's relations with international companies. This agreement is one of the most important and controversial strategic issues in Iran in the 1970s, in the political, economic, and even social spheres. Therefore, its type, nature, implementation, and effects are of particular importance in various analyses of this decade. Accordingly, considering the importance of the aforementioned treaty and its effects on Iranian society in the 1970s, the present study, using a descriptive-analytical method and citing documentary, press, and library sources, seeks to answer the question of what was the nature of the St. Moritz Treaty and what effects did this treaty have on Iranian society? The research findings show that Saint-Maurice was the result of the Shah's belief in the continued presence of the consortium in Iran's oil industries to increase the level of oil revenues. Therefore, although it represented a step forward from a political and legal perspective compared to the first consortium, it was essentially no different from it. Thus, in the 1970s, the intensification of the concentration of power resources in the hands of the government led to the process of oil-based development in Iran.