Novel coronavirus infectious pneumonia is not atypical pneumonia, and the two have more similarities at the same time. Most common coronaviruses are of the genera α and β, with SARS virus and new coronavirus belonging to the genus β. However, there are genetic differences between them, with differences in variability, infectivity, pathogenicity, symptoms and prognosis. Novel coronavirus infections are susceptible in the general population and have atypical onset symptoms and no symptoms during the incubation period, but are infectious.