A new coronavirus, severe acute respiratory syndrome (SARS)-associated coronavirus (SARSCoV), has been identified as the causal agent of SARS. Phylogenetic analyses indicate that it is distinct from the three known antigenic groups of coronaviruses. Similar to other coronaviruses, SARS-CoV contains four structural proteins, including spike (S), nucleocapsid (N), membrane (M) and envelope (E) proteins. All these proteins may induce humoral and cellular immune responses during viral infection. Characterization on the antigenicity and immunogenicity of SARS-CoV is important for developing effective diagnostics, therapeutics and vaccines.