The issue of this paper is what is the definite limit of criminal coercion and how it can be determined. Basically, even if an actor gives threat to the victim, of which substance is within the scope of the actor’s right, that threatening expression can be subject to criminal punishment. In that case, if the actor does the act threatened, his act is out of the scope of criminal punishment. Korean Supreme Court has decided that, in consideration of motive and means of a threatening act, it can be wrong. Herewith, the problem is based on what standard the threatening act’s morality can be taken into consideration. Although morality of threatening act can be considered in the aspect of coercion, extortion and threat, is there any difference among them? The invasion on freedom of victim is the primary legal interest in this issue and also the invasion on freedom of actor should be taken seriously. These two aspects of threatening act should be taken to strike a balance in the area of our daily lives and market. Because the flexibility of decision of criminality of a threatening act makes it possible to restrict our legitimate activities too excessively, kinds of wisdom and principle should be invited in this area. We should note that the method of Korean Supreme Court of deciding criminality of verbal threatening is a wide scope of consideration of circumstances of an actor’s motives, means, benefits and disadvantages of his acts, etc. Also, the current interpretation of coercion, extortion and threat in Korean Criminal Code has paid more attention into violation of general morality in our society, rather than personal right to freedom from threatening expression. This interpretation seems to invite so various consideration of immorality of an actor’s threatening act. The standard of consideration of the cases in issue should be more specified. If it cannot be, it should be subject to constitutional review, based on principle of freedom and clarity. In America, If freedom of expression is in issue, the words existing in the provision of criminal punishment should be more rigorously reviewed. In Lewis v. City of New Orleans, the New Orleans’ criminal provision make it an offense “wantonly to cures or revile or to sue obscene or opprobrious language toward……” The supreme court of New Orleans strike down the provision in violation of the First Amendment, because it is too vague and general for the purpose of the Amendment. After the court's decision, the New Orleans legislator revise the provision, that you can be subject to punishment, if you falsely accuse some person of a crime or testify falsely or provide false information. By focusing on the wrongfulness of expression itself, the provision provide some restriction on punishment of an actor who expresses something within his right but with some inappropriate and base motives. Still, there remains flexible possibility of interpretation that must be a great challenge of that area.