Abstract The purpose of this thesis is to elucidate John Rawls’s claim of the priority of the right. In issue concerning the way in which the major social institutions distribute fundamental rights and duties and determine the division of advantages from social cooperation, Rawls argues against classical utilitarianism that it defines the right as the maximization of the good and that it gives priority to the good over the right. In A theory of Justice, Rawls proposes to view the right as the prior. For Rawls, the right is prior to the good in two senses: the epistemological sense and the moral sense. The former means that the principles of justice can be derived in a way that does not presuppose any particular conceptions of the good, and the latter means that the principles of justice set limits to permissible conceptions of the good and ways of life. In this thesis, I begin by examining how Rawls justifies the priority of the right in terms of the idea of the fairness and his design of the original position. Next, I analyze and assess Michael J. Sandel’s criticisms, which argue that such priority is based upon a defective conception of agency. I point out that, with the methodological clarification in his later theory, Rawls can reply to Sandel’s criticisms effectively. Third, I analyze and assess some criticisms about the desirability and the feasibility of the priority of the right. In conclusion, I point out that, through proper interpretation and modification, Rawls’s claim of the priority of the right is both desirable and feasible; hence can be accepted as the basis of the theory of social justice.