For rethinking the Anthony Giddens's theory on “Reflection”, it is necessary to reconsider his general approach to social reality, and then, situating the concept of “reflection” in the context of his general approach. Thus, three-steps will be studied in the article: First, Structuration theory that is most important opposition in his social theory. Then, Giddens's notion of tradition and modernity. For Giddens, human history share in two “episodes”or “discontinuities” that is completely separated. And third one, Giddens, looks discontinuity points as specific time and place interruptions. To accomplish these three steps, First, we get a model of the process of modernity. And then, we will focus on Giddens's theory of reflection. Finally, we extract concepts essential to explore the tradition.