Abstract: Democracy is not only a kind of ideal , but also an opinion. In the co urse of practice, it is expressed by the institutional run mode in the procedur al sense. Although the democracy played a large role in the opposition of monarc hical power autocracy, it lost the positivism along with the accomplishment of the democratic state's construction. Unexpectedly, it sometimes can cause a terr ible action, which is called "the absolutism of the majority". But finally, th e modern western countries find a democratic constitutionalist way to ensure tha t democracy work well under the protection of systems.