In modern social practice,Legitimacy is the most primary problem.And the public character is the concrete reflection of legitimacy in modern archives work.The significance of public character consists in the public character of starting point of archives work,universality of beneficiary object of archives work and isotropism of archival service. Therefore,if we want to achieve the public character requirement of archives work,we should use our train of public character thinking to improve our current archives management system and operating mechanism.