Talcott Parsons’s sociology of Christianity constitutes the main point of this article as one of the most important functionalist sociologists. This article includes partial information about his general theory of religion. According to Parsons principles of Western and American modernization arise from Christianity from an evolutionist perspective which is formed by historical and empirical data. There are five chapters in the article. In the first part, there are Parsons’s point of view about religion and Christianity, general information about his studies on Christianity, also his ideas about the first period of Christianity. In the second part information on Parsons’s comparisons of East and West Church can be seen. His ideas about the effects of Protestantism especially Calvinism on modernization have been descriptively explained in the third part. The next part is about his views on American Christianity and the pioneering role of America on economical and political modernization. In the fifth and result section, what Parsons think about religion in modern society is being critically considered. The aim of this work is reminding how can be contributory the Parsons’s functionalist and Durkheimian paradigm. Otherwise emphasizing the hesitation of using “civil religion” and “secular religion” terms when he identifies holiness and spirituality is another aim of this study. Lastly, the idea of Parsons’s sociology of Christianity has a subjective role on legitimating American modernization or 20th century American society is another crucial point Talcott Parsons’s sociology of Christianity constitutes the mainpoint of this article as one of the most important functionalistsociologists. This article includes partial information about his generaltheory of religion. According to Parsons Principles of Western andAmerican modernization arise from Christianity from an evolutionistperspective which is formed by historical and empirical data. There arefive chapters in the article. In the first part, there are Parsons’s point ofview about religion and Christianity, general information about hisstudies on Christianity, also his ideas about the first period ofChristianity. In the second part information on Parsons’s comparisons ofEast and West Church can be seen. His ideas about the effects ofProtestantism especially Calvinism on modernization has beendescriptively explained in the third part. The next part is about his viewson American Christianity and the pioneering role of America on economicand political modernization. In the fifth and result section, what Parsonsthink about religion in modern society is being critically considered. Theaim of this work is reminding how can be contributory the Parsons’sfunctionalist and Durkheimian paradigm. Otherwise emphasizing thehesitation of using “civil religion” and “secular religion” terms when heidentifies holiness and spirituality is another aim of this study. Lastly, the idea of Parsons’s sociology of Christianity has a subjective role onlegitimating American modernization or 20th century American society isanother crucial point.Talcott Parsons, as one of the most important functionalistsociologists, considers religion both theoretical and historical/empiricalperspectives. His sociology of religion constitutes of a crucial synthesiswith analytic, theoretic and empirical/historical materials. The role ofmodernization through associating needs of the system with empiricworld leads him to analyze the history of Christianity. In this study hishistorical analyses of Christianity and the correlation he put between themodernization of West and Christianity (especially CalvinistProtestantism) will be considered. Although K. Marx and M. Weber, associologists in capitalistic world, considered the analysis of moderneconomical structure, Parsons was mainly interested of the completeanalysis of modernization. According to him American society is the mostimportant and dominant case of modernization and this situation is anoutcome of combined French democratic revolution and British industrialrevolution which this combination can be seen in no European country.When he tried to explain the success of American modernization, he alsoconsidered Christianity with its evolutionary/modernizing function.Parsons acknowledged institution of religion as the forth evolutionaryuniversals along with relationship, language and technology, butspecifically Christianity is the most evolutionary religion among others.According to him, Christianity makes its modernizing and evolutionaryfunctions actual by using cultural heritage and providing moralmotivation to religious people, but not directly manipulating political andsocial life. Therefore, from one side society getting more secularizationwhich means differentiating religion and politics, on the other sideProtestantism (or Christianity) maintaining its informal control on societybecause cultural norms are formed by religion. American ethos is areflection of institutive and cultural Christianity (Protestantism); also, allattempts of secularization constitute an expound of Christian patterns insecular world.Parsons’s interest of religion evolves through his curiosity onmodernization and evolution. According to him the evolution begins withAncient Greece which is the cultural back ground of Jewish and Christianculture. And this process respectively continuous with the emerge of theintuition of the church, separation of western church from EasternChurch, the advanced institutionalization of Christian societies,Protestant reformation and developments through modernization. Amongthese, the most important step is Protestantism. Because Parsons claimsthat turning point for modern society is not the industrial revolution in18th century but the Protestant movement in 16th century. At this pointhe is not agree with the