Based on original Greek text, this paper proposes a philosophical hermeneia on Plato's dialogue Phaedo. After a brief evaluation of the historical importance and scrutinization of the content of the dialogue, this paper proceeds to the discussion of the following topics: First of all, the significance of aisthesis in the formation of human knowledge is dealt in Part III. In Phaedo, aisthesis plays two phenomenologically antithetical roles in man's grasping truth. On the one hand, aisthesis, as related to body but not to soul, gives us the confusing and inaccurate impression of the phenomenon, and thus constitutes the hindrance from the acquisition of true knowledge. On the other hand, Plato emphasizes the importance of aisthesis in his recollection theory, and regards it as a clue to remind us of the forgotten ideas we had seen in the world of ideas before our birth. However, the dialectical synthesis of these two position is not treated in this dialogue. Part IV discusses the theory of learning as recollection in Phaedo. According to Plato, human soul, preoccuppied with proeidenai (a priori knowledge), recollects the forgotten ideas through the clue of sensation. Thus theory of recollection seems to indicate the liaison between intelligibles and sensibles, which liaison strongly binds the dependence of sensibles to intelligibles. The metaphysical foundation of Plato's theory of recollection is theory of ideas, which is expounded in the fifth part. Ideas as intelligiblia, are pure, eternal, immortal. Sensible things, undergoing Changes, are incomplete, destructible. Ideas play the role of prototype, which participates in the world of sensibilia, and mrake the sensibilia as their form-copies. The theory of idea is the strongest reason for the demonstration of Plato's immortality of human soul. Accordingly, the explanatory power of idea and hypothetical methodology of Plato are discussed in Parts VI & VII. In contrast to Prosocratic aetiotocical and mechanistic explanation of the cosmos, Plato accepts [idea exists] as presupposi-tion and gjves the cosmos teleological interpretation. Therefore ideas in Phedo, are necessary and sufficient condition for our understanding of the world. Part VIII presents a critical analysis of Plato's demonstrations of immortality of soul. The first demonstration Plato proposes, appeal to presupposition of the generation of everything from its opposite. Life and death, as two opposites, generate one from the another and have their two processes of generation in eternal airculation. Thus soul must exist in another world beyond human sensation. The second demonstration appeals to the theory of recollection. According to theory of recollection, as stated before, only soul can recollect a priori idea. Therefrom we can conclude that the soul has lived and ex-perienced the. world of ideas before its incarnation. The third demonstration appeals to the theory of resemblance. Human soul in contrast to destructible body, is more like the divine, invisible, eternal being and thus is immortal. All the demonstrations are based on the theory of ideas. The most defective point of Plato's demonstration lies therefore in the tautological proof with the presumption of the existence of ideas. Furthermore, in the process of demonstration, Plato confuses soul with life, linguistic opposites with the ontological ones, harmony with soul etc. In spite of the deficience in demonstrating the immortality of human soul, this dialogue cuts a very important figure in the history of western philosophy. Imm. Kant's theory of a priori form in epistemology and his division of the world into phenomenon and noumenon may trace its origin to this dialogue. The dualism of body and mind in western philosophy from R. Decrates on was consolidated by Plato's demonstration of the immortality of human soul in Phaedo.