The principle of good faith as the one of the fundamental principles of civil law,not only directly reflects the essence of civil law,but also the performance of the legislator's intention,but it is also citizens should comply with the minimum of moral bottom line.This principle is of great significance not only in legislation,in judicial practice,play an equally important role.Of good faith principle is that economic activity in the market as a fundamental rule of law,but also we are implementing the CPC Central Committee and the basic principles of rule of law,the principle of good faith is a kind of moral meaning of legal norms.