RH12 is a dual inhibitor for SARS-CoV-2 related RNA-dependent RNA polymerase ( RdRp , IC 50 is 4.42 nM) and human transmembrane serine protease 2 ( TMPRSS2 , IC 50 is 4.2 nM). RH12 exhibits antiviral efficacy. RH12 inhibits viral replication and absorption, and exhibits a 90.5% virucidal effects on Vero-E6 cells. RH12 inhibits cell viability of Calu-3 with an IC 50 of 17.5 nM.