Cap-dependent endonuclease-IN-9 is a potent inhibitor of cap-dependent endonuclease ( CEN ). Not only can Cap-dependent endonuclease-IN-9 inhibit influenza virus well, but also has lower cytotoxicity, better in vivo agent kinetic properties and in vivo pharmacodynamic properties. Cap-dependent endonuclease-IN-9 has strong inhibitory effect on RNA polymerase activity of A virus (extracted from patent CN112521386A, compound VI-1).