The Korean Criminal Act §27 describes "Even though the occurrence of a crime is impossible because of the means adopted for the commission of the crime or because of the mistake of object, the punishment shall be imposed if there exists a dangerousness. But the punishment may be mitigated or remitted". From the point of comparative study, the contents of the Korean Criminal Act §27, is very unique. That means, there is few countries which have such a provision like the Korean Criminal Act §27. So there have been so many competing opinions surrounding the meaning of dangerousness and that of impossiblity of crime occurrence. The purpose of this paper is to suggest a reasonable way of construing the concept of dangerousness and that of impossibility of crime occurrence after analysing the many competing opinions.