This study concerns the role of costume in Shakespearean comedy from the viewpoint of the role theory. The term “role” has been used to represent the behavior expected of the occupant of a given position or status. A specific role can not be successfully performed without the aid of the costumes. Costumes are adopted in relation with a specific role. The term ‘role’ had been borrowed from the drama. The similarity between the role on the stage and the role of the social man had been recognized. The typical examples in which the costume help to make access to a specific role and can be effectively exploited for the performance of the role are manifested in the comedies of Shakespeare. Thus, our goal in this study is to analyze the role of costume which appears in Shakespearean comedy from the viewpoint of the role theory. The role of social status and position reflects sex, age, occupation, class, economic position of the characters. In his works, the crown and the mace represented not only the throne but also a previllege and supreme position. The situation role of costume could be widely used for visualizing the psychological situation and external environments of the characters on the stage. The disguise role hided one`s status, thereby makes possible acting other`s position. And the disguise role can bring about the change of status, age, sex, occupation, and atmosphere. The costume also could symbolize the social status, position, rank, occupation, and the situation, and functioned as a media for delivering messages to others. The costume performed the role of the physical and psychic protection, and provided its wearer with consolation and peaceful mind. The costume reflected the costume of a society through its wearing condition and wearing configuration. The results obtained from this study can provide useful cues for understanding the role action in the social structure. This kind of understanding reveals the costume phenomena in real life, allows one to perform roles properly and efficiently, and opens our insight on the overall aspects of the costume culture.