Just as Adam Smith is one of the representatives of classical utilitarianism,John Rawls is one of the representatives of contemporary liberalism, through criticizing utilitarianism, he establishes a liberalism justice theory with a conception of fairness and justice as its core idea. Rawls expresses his appreciation for Adam Smith and criticizes the latter’s theory of justice in his works. But Rawls’ response to Smith’s thought is very rough. Whether Rawls deliberately avoids Smith’s moral philosophy is of great significance to understand the theories of justice between liberalism and utilitarianism. By comparing the justice theories of Rawls and Smith, we will reveal the relationship between them, judge the rationality of Rawls’ criticism of utilitarian justice theory, and evaluates the influence of Smith’s justice theory on contemporary political philosophy. Adam Smith puts forward a theory of justice from the view of a sympathetic and impartial spectator in his The Theory of Moral Sentiment. First of all, Smith believes that moral judgment is based on such an assumption that an impartial spectator has an ability of sympathy. Secondly, Smith further investigates and summarizes the characteristics of ″an impartial spectator″: impartiality; interest neutrality; understanding the truth of things, and he derives the legal system of justice from the assumption of ″an impartial spectator″. Smith distinguishes justice from benevolence. He concludes that justice is a negative virtue, benevolence is a positive one. Rawls’ criticism of Smith’s ″an impartial spectator″ theory of justice focuses on three aspects. Firstly, Rawls believes that the definition of impartial spectator does not make any assumption about the possibilities of the principles of justice. Secondly, Rawls criticizes that ″an impartial spectator″ only takes some preferences to be satisfied as an important measure to formulate social justice principles, without considering the aims of those preferences satisfied, and neglecting the satisfaction of some individuals’ preferences at the expense of others’ interests. Finally, Rawls believes that ″an impartial spectator″ is the integrator of simple preferences. However, Rawls’ comments on ″impartial spectator″ is not the truth as Smith’s interpretation on that notion. Rawls misreads Smith’s justice theory to some extent. Firstly, Rawls ignores the three characteristics of ″impartial spectator″: disinterested, uninvolved and not personally affected. In fact, it is the same as the ″mutual disinterestedness″ characteristic of the parties in the original position that Rawls assumes in his A Theory of Justice. Secondly, Rawls ignores that what Smith pursues is not a society with the maximum utility and the best average wealth. Smith is more concerned with the realization of justice. His theory of justice gives priority to the interests of the middle and lower classes in a society, he wants to unite the forces of the middle and lower classes, restrain and divide the interests of the upper class to realize the maximization of social interests. Rawls ignores the important contribution of Smith’s theory of justice to making some balance of the interests between social classes. In fact, Smith’s ″impartial spectator″ and Rawls’s ″the parties behind the veil of ignorance″ are two notions corresponding with one another. Smith deducts from sympathy to an impartial spectator’s justice, while Rawls deducts from the individuals in the original position to a conception of justice as fairness. Smith’s ″justice is the fundamental of society″ is similar to Rawls’s ″justice is the primary virtue of social institutions″. Therefore, there is a secret association between the justice theories of Smith and Rawls. And the sense of justice,or the sentiment of justice,is a key to show that secret, one belongs to Rawls, the other to Smith.