This paper is to examine the problems of gender in the korean criminal law system. There are many gender-related problems in this area. In Korea, there are established legal regulations concerning, for example, sexual harassment, rape, sexual assaults in the domestic relationship, adultery, abortion, pornography, prostitution and so on. But the basic conception on which these regulations are based is not one and the same, but heterogeneous and even contradictory. While formerly the de-criminalization movement based on legal liberalism asserted that some immoral behavior done between the consenting adults not be treated as crime, feminist movement reversed this liberal trends and insisted that some behaviors which were not conceived as crimes should be treated as crimes(for example: domestic violence) and that must be enacted by the legislature. Based on the feminist conception of crime, the korean legislature enacted several acts against domestic violence and sexual assault. In this paper the author examines these gender-related criminal behaviors and the conceptions of regulating those kind of deeds and also the acts enacted against gender-related violence. The author, taking feminist point of view seriously, asserts that some behavior that, even though formerly not conceived as crime, has harm to the victims, should be treated as crime, but some behaviors that are only morally wrong but has no harm to others should not be treated as crime(i. e. prostitution between the consenting adults).