Ancient and modern in China and abroad, "honesty" is always an ethical constraint of people’s behavior. Along with the development of commodity economy and the establishment of market economy, the rule of law has replaced moral regulation and become the basic maxim of our daily life. "What the rule does not forbid is all free" is the spirit of "rule by law", which firstly advocated by all people comes out all kinds of disorder in some social area without law. These disorders include the breach of trust. In any country, the government’s breach of trust is the biggist and the worst. How to prevent the administrative subject body from the breach of trust and control their behaviors, and how to ensure interests of the administrative counterpart are the problems we all have to face. Centred on how to establish the administrative principle of good faith, this paper includes the contents in the following chapters:First part discussed and analyzed the connotation of the administrative principle of good faith;Second part probed into the academic significance and the practical value;Third part introduced several legislation practice in establishing the administrative principle of good faith, including the modals of Germany, the UK, the USA, Portugal and Chinese area of Taiwan;Forth part simply summarized the status quo of our establishing of the administrative principle of good faith, and pointed out synoptically the matter in hand;Last part based on the above mentioned, arrived at the conclusion that we should establish the administrative principle of good faith as the highest principle of the administrative law and enhance the establishment of the specific regulations.