It is difficult to compare the novel coronavirus with the SARS virus because both belong to the same coronavirus family, and the novel coronavirus has never been found in humans before. From the current clinical cases, there are some severe cases and some mild cases of novel coronavirus, and the virulence and pathogenicity of the virus need to be analyzed based on more clinical data. The major difference between the novel coronavirus and SARS virus is that SARS virus is infectious only in the presence of fever or pneumonia, whereas the novel coronavirus is infectious even in the incubation period without symptoms.