Abstract: The actuality of freedom can only be demonstrated on the basis of rational being or of the process of "Dasein";the actuality of freedom is indicating necessary "factual acting" of existence of pure principles which determine the experiential objects;freedom, as the essence of human being, is both transcendental and active, and necessarily comes out in the unity of world centered by human being;every way to further study on freedom results from the new choice and deconstruction based on the old theories, this is true for both Kant and Heidegger;thus when we try to hold on freedom, we are in fact advancing towards the path of self-being, and insight the truth of "Dasein".