Based on the concepts of Fundamental-ontology and the methods of Phenomenological-Hermeneutics in ”Being and time” (Heidegger, 1927/2008) , this paper will try to elucidate Martin Heidegger's (1889-1976) thesis about Autonomy, which will be analyzed through the discussion of ”self ”and ”self-constancy” (Selbst-säindigkeit), in order to demonstrate that ”responsibility” could be the ontological ground of ”independence” and ”autonomy.” Without responsibility, one would not be able to return to his itself. Consequently, one would not enjoy autonomy nor realize the truth of existence.Strictly speaking, Heidegger's Autonomy has two grounds: one is the In-each-case-mine (Jemeinigkeit), and the other is responsibility, which could be defined as the response to itself. In-each-case-mine in Being and Time (1927) is manifested mainly in the analysis of the phenomenon of Death. In his discourse on the essence of life in the context of the structure of existence, Heidegger points out that ”death”, in the case of each individual, belongs to that individual, and is therefore ”my own death which belongs to me only, and would not be shared with anyone else nor replaced by anyone else's death.”In the context of daily life, however, human beings tend to have the mentality of trying to escape from their own deaths. Heidegger contends that only if human beings realized the In-each-case-mine of death and its connection with everyday life could they truly be freed from the fear of death. They could, therefore, return to the self and remain constant in the world. As a result, they could hear the call of conscience and maintain their true autonomy.In light of the above-mentioned thesis in ”Being and Time”, this paper will demonstrate how ”freedom” and ”respect” would become the representation of autonomy and responsibility.