The main protease (M(pro)) of severe acute respiratory syndrome coronavirus (SARS-CoV) plays an essential role in the extensive proteolytic processing of the viral polyproteins (pp1a and pp1ab), and it is an important target for anti-SARS drug development. SARS-CoV M(pro) is composed of a catalytic N-terminal domain and an α-helical C-terminal domain linked by a long loop. Even though the N-terminal domain of SARS-CoV M(pro) adopts a similar chymotrypsin-like fold as that of piconavirus 3C protease, the extra C-terminal domain is required for SARS-CoV M(pro) to be enzymatically active. Here, we reported the NMR assignments of the SARS-CoV M(pro) N-terminal domain alone, which are essential for its solution structure determination.