The efforts Oedipus has made against the oracle can be seen as using personal rationality to confront the destiny that the God have already arranged.Through the tragedy of Oedipus, Sophocles shows to people the irreconcilable contradiction between ra-tionality and destiny. By analyzing the rational elements in Oedipus'actions and the role of God in Oedipus'tragic destiny, this paper aims to discuss the relationship between rationality and destiny so as to further represent Sophocles 'views on theocratic and humanistic rules.