The social function of literature has been questioned since its birth. About 330 BC, Aristotle gave a firm answer to it: Catharsis. In the medical practice of Hippocrates and his school, and later in the Asclepian therapy, there are studies of the cathartic processes of diarrhoea, vomiting, and menstruation. Catharsis can be considered to be mainly the purgation, purification and cleansing in order to establish a harmony and healthy relationship between men and the gods. As is well known, since Freud, Catharsis is an acknowledged term in Western psychotherapy and everyday use; among them, literatherapy also counts on the cathartic energy. Literature, which is the representation and imitation of life, gives us the imaginary space to cure illness of modern society. Therefore, literatherapy has been established to systematize the medical function of literature. However, the attempt to relate literatherapeutic function with Oriental medicine seems to be neglected in the major academic field. In the method of Oriental Neuropsychiatry, psychiatric illness can be cured either by transforming emotion into another object or by evoking the counter-feeling of the superfluous (thus ill, for superfluity is illness itself) psyche, with "words," literature. Moreover Oriental medicine claims that body and mind are one, and closely linked to each other, enhancing or aggravating each other; therefore it may give us a more profound ground to justify literature as a useful psychotherapeutic method. In this respect, it is worth investigating the power of literature in terms of Oriental Neuropsychiatric therapy. A contemporary British novel Atonement is one of the outstanding examples that portrays various kinds of illness of the modern society, such as violence, anger, suppression; and it transforms the ritual of atonement into the artistic language that evokes the plethora of emotion and feelings. This study examines literatherapeutic function of McEwan's Atonement from the perspectives of the Oriental Neuropsychiatry and ultimately analyzes the inter-complimentary relationship of Catharsis and Oriental psychotherapy.