This study examines One of the socio-cultural categories of contemporary Iranian history, The rate of early marriage for girls in in Tehran city During the last two decades of the Pahlavi regime. This article, In other words, With emphasis on the project of modernization of the second Pahlavi regime during the two decades of the forty-fifty, examines The effects of this modernization project on the Tehran city Focusing on the three indicators of urbanization, the social status of women, and the level of education and literacy in society, And then in the framework of the theory of modernization Analyzes the relationship between these components of the macro-scale transformation at the community level with one of the social phenomena, namely, the rate of early marriage among girls During the same period of time. The research method in this paper is a secondary analysis based on quantitative and qualitative data, in addition, Methods and Tools for the Data collection was the Library and Documentary study that was conducted by taking notes and Calculation of the Statistics and raw data. The findings imply as the second Pahlavi regime's efforts to modernize and develop in the Iranian society increased and as a result, urbanization, the social status of women, and the level of literacy in the urban community of Iran followed a rising trend, On the other hand, Reduced the Early marriage rates for girls.