Freud refined and improved the concepts of the unconscious, of infantile sexuality, and of repression and proposed a “tri-partite account of the mind’s structure” (Zuo, 2005: 97). In his later work, Freud proposed that the human psyche could be pided into three parts:  the id, the ego and the super-ego. Freud came out with a new book in 1923, The Ego and the Id, describing a new comprehensive theory of personality organization. In his opinion, all human’s psychology could be analyzed by the structure which determined human’s behavior. Id is composed of the forbidden desires, being sexual and greedy. It always tries to pursue for the desired pleasure regardless of anything else. The ego acts according to the reality principle. In Freud’s theory, the ego compromises among the id, the superego and reality. It tries to find a balance between the primitive drives and reality while to satisfy the id and the superego. The superego can be taken as the conscience. It tries to behave itself in the society, doing what the external world wants it to.