The secularization in Iran has been the subject of much research, explaining that most studies to measure secularization measure the degree of religiosity of society and the reverse of religiosity is considered secularization. This article claims that secularization is a phenomenon independent of religiosity, and appropriate measures must be taken to measure it. Therefore, the author attempts to show its levels, dimensions and components by limiting the meaning of secularization. The article shows that secularization occurs in three levels: macro, medium and micro, and in three dimensions: social, religious and individual. Social secularization has three components: structural, cultural and organizational, and occurs in three areas: society, politics, and economics. Religious secularization, which manifests itself in the form of "acceptance of customary values, norms and rules" and "utilitarianism", is related to both macro and medium levels. Personalization refers to the secularization of one's motives, values, beliefs, feelings, cognitions, and behaviors.