Sportsmanship and sports ethics are the metaphysical philosophy and spirit slogans of athletes. Sometimes, we will find difficult to define them and give an example. However, we usually ignore them present to the sports rules. In this paper, we not only discuss the relationship between sports ethics and sports rules, but also discuss the relationship between sports rules and criminal law by the "fake household registration" style of sports cheaters. The acts of athletes are restricted by sports ethics, sports rules and sports law. It seems to limit the liberty of athletes and restrain the developments of sports. In this text, we will discuss the concept of "Social Function of law", and make a description of that sports ethics, sports rules and sports law are creating liberties, rather than limiting.