New coronavirus infection is more contagious than SARS in terms of its infectiousness, because the new coronavirus has a long incubation period of 1-14 days, and patients during the incubation period are significantly more contagious even if they do not develop the disease, but SARS patients are generally more contagious only after the onset of symptoms. In addition, the new coronavirus population has a general susceptibility, and the susceptible population of SARS is mainly more middle-aged and young adults. Novel coronavirus infection has heavy and critical types of patients, and these patients may develop acute respiratory distress syndrome or sepsis, which in severe cases can lead to respiratory distress, respiratory failure and multi-organ dysfunction and cause death, and for the comparison of SARS its mortality rate will be slightly higher.