Rumor,in the sense of law,which is gradually being replaced by the term false information,is factual information mainly involving emergent events whose falsity have been proved. The establishment conditions of administrative illegality and criminality of spreading rumor are coincident,which apply to the Three Stages theory system which is the mainstream viewin Chinese criminal law. In the essential factor of constitutive requirements,false information in criminal lawand rumor in administrative lawleave hidden troubles for expanding punishing freedom of expression. In the illegality or consequence of infringement aspect, the criminal lawprovides actual consequence of infringement, and the administrative lawenforcement identifies the danger and threat of rumor with disruption of social order.In the responsibility aspect,both administrative and criminal laws explicitly require intent. Although the legal system should be improved regarding rumors,the establishment of illegality and criminality is still limited,as long as the existing laws are strictly observed.