The first research on the NS1 protein as the non-structural protein of the type A influenza virus was emphasized on the considering of its depressant effect on the composition of the protein of host cell. And now, with deep research, the evolution of its genes and the antigenicity of its protein have been explained. The NS1 protein of influenza virus has the association with the apoptosis induced by the influenza virus, the regulating function of apoptosis has the direct correlation with possibility of producing interference and the cell line infected by influenza virus. The NS1 protein restrained to producing the interferon by infected cell. The NS1 protein plays an important role on the host anti-viral cytokine responses, it possesses nagitive regulation for interferon's antiviral activity, most observation indicated nagitive regulation might associate with the virulence of influenza virus. Furthermore NS1 protein as an inspection antigen to differentiate and diagnose the poultry which was immunized or naturally infected has a very wide prospect, because the traditional vaccine was used extensively.