Abstract The main protease (M pro ) of coronaviruses plays a key role in viral replication, thus serving as a hot target for drug design. It has been proven that PF-00835231 is promising inhibitor of SARS-CoV-2 M pro . Here, we report the inhibition potency of PF-00835231 against SARS-CoV-2 M pro and seven M pro mutants (G15S, M49I, Y54C, K90R, P132H, S46F, and V186F) from SARS-CoV-2 variants. The results confirm that PF-00835231 has broad-spectrum inhibition against various coronaviral M pro s. In addition, the crystal structures of SARS-CoV-2 M pro , SARS-CoV M pro , MERS-CoV M pro , and seven SARS-CoV-2 M pro mutants (G15S, M49I, Y54C, K90R, P132H, S46F, and V186F) in complex with PF-00835231 are solved. A detailed analysis of these structures reveal key determinants essential for inhibition and elucidates the binding modes of different coronaviral M pro s. Given the importance of the main protease for the treatment of coronaviral infection, structural insights into the M pro inhibition by PF-00835231 can accelerate the design of novel antivirals with broad-spectrum efficacy against different human coronaviruses.