The transformation of Criminal Law from traditional to modern is one of inevitabilities of history. In the presence of personal interest, regulating the future behavior by criminal law is also a trend. Since entering the risk society, the connotation and content of legal interest is becoming more abstract, the front protection way of legal interests is expanding, and the base color of legal interest is being covered a kind of “non-human” phenomenon. In the risk society, in order to be aware of the risks of legal interest, prevent legal interest from being weaken and avoid criminal law becoming a tool as criminal policy, protection limit of legal interest should take constitutional principles into consideration, and keep modest and restraint as the limit core. In addition, the ethical baseline of legal interest should stick to the liberalism and humanism. All these aim to maintain the base of legal interest theory.