The concept of action in Heidegger is related to understanding and projection. What Dasein projects is something like the plot in narration. Although narration is not a word of Heidegger, some commentators have a narrativistic interpretation based on historicallity and temporality of Dasein. In this writing we focus on a different interpretation based on fundamental narrativity of Dasein and its relation to action. Our basic thesis is that there is a mutual dependence and hermeneutical circle between actuality and narrativity of Dasein; They are both equal to understanding and projection, so coexist in Dasein' s existential structure. The aim of our discussion is to show that how our actions can be influenced by the way of our narration and interpretation of our life and self-understanding. The analysis of this influence has a basic role in our understanding of the way different narrations such as stories, films, criticisms and…, could affect our behavior and our self-understanding. We find that the understanding of our situation and possibilities can form the kind of our action; Every action as understanding, can open a vast area of possibilities which nonetheless stay hidden. This circle continues perpetually and extends our world.