In Korea there are numerous special criminal laws. They are almost products which were enacted as social needs arose from time to time, but their mass production has a bad influence which damages unity and coherence of criminal law system seriously. Under such a recognition this paper treats legislative structure and characteristics of special criminal laws. To begin with, they have the following common properties in the respect of legislative structure. First, they have strong purpose connected with heavy punishment. Second, there are many regulations in them which overlap those of general criminal law and inflict excessively severe punishment. Some of them are obviously against principle of proportionality in punishment. Third, their contents are very complex. In other words, they regulate various fields, namely not only the substantial but also the procedural or/and the administrative. Fourth, they have many exceptional regulations to widen the range of criminal punishment, and it is certain that some of them are contrary to principle of responsibility. Based on these characteristics, it can be said about the foundation of special criminal laws in two ways. First, in a way of rational theory there is no foundation in them. Because they are not in harmony with criminal law system and occasionally with constitutional law. Second, in a way of real logic they seem to have a foundation. It is no other than crime prevention and deterrence. But in my opinion this aim seems not to have been accomplished. Thus, there is nothing left except one in special criminal laws. It is just a meaning as symbolic function.