The purpose of this paper is to consider most critical issues of mystical epistemology in Rumi and Bonaventura once the views on subject, reality of the world, and the possibility of knowledge were expressed. This research referring works of Rumi and Bonaventura studies this issue through a descriptive-analytical method. Rumi and Bonaventura recognized three stages of human recognition realm including sensory, rational and illuminative recognitions. They both believe that achieving real knowledge and recognition requires revelation in addition to reason. In their perspective, the spirit is the unique intuitive and mystical knowledge tool such that Bonaventura extends its epistemology based on illumination referring this stage the supreme level, intuition and unity to God. At this stage, human being is not merely a definite subject rather an external phenomenon influencing knowledge trend. Rumi states that real treasure between God and world is only recognized by mysticism not through discussion and rational reasoning.