Psychoanalytic criticism is an important criticism which is usually employed to analyze the literary texts. This article studies the characters of Sohrab, Rostam and Kavous in "Rostam and Sohrab" story. Firstly, the character of Sohrab is examined as the "passionate character" because of the existence of some especial traits in him, such as: ambition, courage, seriousness, zeal for attaining his goals, love relationships, and interest in fighting for the sake of power. Secondly, Freud's idea about Id, Ego and Super-ego and their relations to these three characters, Sohrab, Rostam, and Kavous, are studied. Actually, these three characters are reflecting these three concepts proposed by Freud. Thus, the conflict among these characters is interpreted as the conflict between Id, Ego, and Super-ego.