Coronaviruses are a group of enveloped viruses with non-segmented, single-stranded, and positive-sense RNA genomes. Human coronavirus infection causes respiratory diseases with mild to severe outcomes. In December 2019, a new outbreak of the novel coronavirus disease 2019 (COVID-19) emerged in Wuhan, China and spread around the world. Genomic analysis revealed that severe acute respiratory syndrome coronavirus (SARS-CoV-2) is phylogenetically related to SARS-like bat viruses. The intermediate source of origin of SARS-CoV-2 and its transfer to humans is not known; however, it acquired efficient human-to-human transmissibility while retaining human pathogenicity. Spike protein of SARS-CoV-2 has the potential furin-like cleavage site may play a significant role in virus entry. Receptor binding domain (RBD) of SARS-CoV-2 attaches with angiotensin-converting enzyme -2 (ACE2) of epithelial cells. The SARS-CoV-2 genome encodes four major structural proteins: the spike (S) protein, nucleocapsid (N) protein, membrane (M) protein, and the envelope (E) protein are involved in assembly, budding, envelope formation, and pathogenesis. Notably, E protein act as viroporin and there is no mutation found on E protein among SARS-CoV-2 strains. At present, the case fatality rate is estimated to range from 6 to 7%. COVID-19 is now a public health emergency of international concern. There is no clinically approved antiviral drug or vaccine available against COVID-19. This review summarized the latest information on the structural and molecular biology infectivity, host immune response and molecular immunopathology of the SARS-CoV-2.