Abstract：Although there are many opinions on the legitimacy of state power in different countries and periods ,akey problemis whether thelegitimacy is acknowledgedby the wholenation .Thelegitimacy of state power in modern society is based ,conceptually ,on the consensus of popular sovereignty and the rule of law;formally , on related laws , and in reality , on justice to the interests of the people . The conceptual ,formal ,and real foundations of legitimacy exist independently , but each affect the others . Their differences couldreflect the real situation of a state's power in a country; the fewer the differences , the better the situation . Modern state power will exist harmoniously only if the three are adjusted continuously with social development .
