Death is such a deep and mysterious concept that has always been occupying the human mind. In any era of history, different nations have given different responses to what death is and why it exists according to their social, religious and political conditions, and they have approached it distinctly. As it can be seen in many mystical works, thinking of mortality is of great importance in Sufism, whether these thoughts are rooted in thanatophobia or, conversely, in welcoming death as a way to perfection. In this library research, the structures of mortality and thinking of death in Sufism are investigated from a sociological and cognitive perspective through deliberation on the concept of death and its typology in Sufism.The study of theories by scholars such as Durkheim, Rank and Freud and their comparison with Sufism intellectual foundation indicates that the concepts such as immortal double and immortality of unconscious mindhave greatly contributed to the course of death and finitude thoughts in mysticism and Sufism.