The eighteenth century is doubtlessly an astonishing chapter in human history. Following America's independence that brought the first new democratic country to the world, the French Revolution further aroused tremendous political effects all over Europe, shocked the foundation of feudalism, and announced the advent of democratic era. Confronted with all these historical impacts, Tocqueville has achieved profound understanding and retrospection on the inevitable prevalence of democracy. The concept of liberty plays a very important role in Tocqueville's theory. As the wave of democracy crashed outmoded institution of feudalism, it also caused people to grow. assimilated, or even philistine. In light of this, Tocqueville proposed that, in order to preclude domination and slavery, people should more actively grasp their liberty and develop the habitude and spirit of participating public affairs. Therefore, township and jury system in American tradition, as well as individual activities of organizing secondary civil groups through gilds, are highly regarded by Tocqueville with democratic connotation. From this viewpoint, Tocqueville's great expectation on liberty is essentially different from "human's liberty from interference" of contractarian liberalism but is in harmony with the conventional idea of people's "agency" in republicanism. This connotation of liberty, however, doesn't imply clashes without limit but suggests reasonable and restrained political participation within the schema of stable political institution. Thus, the concept echoes the conventional appreciation upon institution in roman republicanism. The researcher regards the integration of the aforementioned two aspects as "liberty of institutional republicanism". This research intends to embody the republicanism value in Tocqueville's theory with an expectation to broaden the definition of liberty.