The new coronavirus is so aggressive that it reminds us of SARS (Severe Acute Respiratory Syndrome, an acute respiratory infection caused by the SARS coronavirus) in 2003, how is the new coronavirus related to the SARS coronavirus? This time, the new coronavirus is so aggressive that it reminds people of SARS (Severe Acute Respiratory Syndrome, an acute respiratory infection caused by SARS coronavirus) in 2003, so how is the new coronavirus related to SARS coronavirus? First of all, according to the current study, there is no subordination between 2019-CoV and SARS-CoV, and there is no statement that the novel coronavirus belongs to SARS coronavirus, both belong to the same coronavirus. Coronaviruses are a group of pathogens that mainly cause respiratory and intestinal diseases. Under the electron microscope, these viruses appear to have many regularly arranged protrusions on the surface, resembling the crown of an emperor, hence the name “coronavirus”. Our 2019-CoV and SARS-CoV are two variants of the same coronavirus, which are at most distant cousins. Secondly, 2019-CoV and SARS-CoV share 79.5% gene sequence similarity and enter the host cell in a similar way, both entering the host cell through the surface Spike protein connected to the ACE2 receptor, but they still have many differences, for example, the RBD region of the Splike protein of SARS-CoV has five important residues, while 2019-CoV has only one of them. It is with these differences that the infectiousness of the two is not the same. 2019-CoV has a stronger binding to the human ACE2 receptor in the recent literature, and the traffic is more developed than in 2003, as well as the higher population density in Wuhan. CoV is much lower than SARS-CoV. (The following table shows the comparison between 2019-CoV and previous infectious viruses, CaseFatalityRate disease and death rate, R0 basic contagion coefficient: refers to the average number of how many other individuals a person infected with a certain infectious disease will transmit the disease to without external intervention, while all people have no immunity) In addition, the two sources of transmission are relatively similar. The source of the SARS outbreak in China in 2003 was the Chinese chrysanthemum-headed bat, while the intermediate host was the fruit civet. The natural host of the novel coronavirus may also be a bat, but the specificity has not been determined, and the intermediate host may be a pangolin, or there may be multiple intermediate hosts. The transmission route is also mainly airborne, contact transmission is secondary, and fecal-oral transmission is still controversial. Although the number of new coronavirus infections has exceeded that of SARS coronavirus, and more “cunning” than SARS coronavirus, but the death rate is much lower than SARS, and we now have more experience, higher level of medical care, we will be able to defeat the new coronavirus like SARS.