SARS-CoV-2 is a positive-sense single-stranded RNA virus (+ssRNA) with round or elliptical particles, a diameter of about 80 to 120 nm, and about 30,000 nucleotides long. Like other HCoVs, SARS-CoV-2 has four major structural protein, including S (spike), E (envelope), M (membrane), and N (nucleocapsid) proteins. S protein plays an essential role in the virus infection of SARS-CoV-2. S protein of SARS-CoV-2 which higher affinity than SARS-CoV, mediates entry into host cell through binding angiotensin-converting enzyme 2 (ACE2) and then primes through the serine protease TMPRSS2. After the viral entry into host cell, RNA-dependent RNA polymerase (RdRp, also known as nsp12) through binding co-factors nsp7 and nsp8 etc. catalyzes the synthesis of viral RNA. The At last, SARS-CoV-2 produces three virulence factors (Nsp1, Nsp3c and ORF7a) to interfere human immunity and assist immune escape. Recently, L. Zhang et al has revealed the crystal structure of SARS-CoV-2 main protease (Mpro, also called as 3CLpro) which is closely related with the reproduction of the virus.