This paper will study meanings and backgrounds of public trust from points of concepts and governmental function, and the way that public trust can transform from ideas to concrete public policy. Under multiple and complicate local situation, local government can’t afford resources and abilities to fulfill outside needs, and will result the ”distrust”, which means local government lost accountability to people. So, the function of public trust is not only to integrate different interests but also can provide legitimacy to local government. In the implementation sphere, public trust should not be seen as panacea or moral symbol, and it is an interactive model which needs to breed in long time. By this process, it will play buffer role to solve problems between people and local government, and may create win-win synergy.