MITHRAISM, as one of the oldest Iranian religions, used mythical SYMBOLS to lead its followers which can be the leader of the audience for an accurate understanding of the various aspects of these SYMBOLS in this ritual. Mehrabeh, as the sanctuaries of the followers of this ritual, have a symbolic structure; they are either built in natural caves or form a cave. In this study, based on the mythological and religious views of Mircea Eliadeh, the cave symbol and the its functions in various texts, have been investigated, using the analysis of Eliadeh in its various works, the authors have tried to study the symbolic function of the cave in the religion of MITHRAISM. The symbolic function of the cave in MITHRAISM, should be categorize in the subtitle of the "symbolic place of the ritual of sympathy", which is itself linked to "the womb of the mother earth" and "the inner and unconscious world", Based on the new classification presented in this study and study of the Eliadeh's works...