Heidegger’s critical interpretation of Kant’s concept of the transcendental imagination has been taken as one of the most ambiguous and obscure interpretations since its beginning. The essay aims to clarify two starting points made by Heidegger in his criticism against the traditional understanding of the Kant’s concept. The first one consists in that people often focus their interpretations more or less on the concept of the power of imagination (productive and reproductive) rather than on the transcendental power of imagination in Kant. Different from but also related to the first misunderstanding, the second one sees the power of imagination serving merely as an intermediating mid-point or the third faculty among the two other capacities or faculties like sense and apperception, rather than as the original central ground or the transcendental “hidden source” of human cognition and knowledge itself. Based on the above understanding and clarification, the essay attempts to show that Heidegger’s understanding of the genuine Kant’s power of imagination should be neither a “Dichtungsvermoegen” of a soul or human mind in psychological or anthropological sense, nor a “transcendental” power of imagination in a sense of epistemology, i.e., something which is prior to any experiences but makes all of them possible. Rather, it is an ontologically more primordial “grounding” ”Einbildungskraft” which is not only prior to our experiences and their objects, but also make both the objects and experiences existentially possible.