The circulation of H9N2 viruses throughout the world, along with their expanded host range, poses a potential health risk to the public, but the host responses to H9N2 virus in mammals were little known. To obtain insight into the host immune responses to the avian H9N2 virus, the expressions of both cytokines and chemokines in the lungs of infected mice were examined by real-time polymerase chain reaction and enzyme-linked immunosorbent assay. We found that interferon gamma (IFN-γ) was the dominant antiviral component, and IFN-γ-induced protein 10 kDa, interleukin 6, chemokine (C-C motif) ligand 5 and macrophage inflammatory protein-1 alpha all played a role in pro-inflammatory responses to H9N2 viruses. In conclusion, this research can make us further understand the infection characteristics of H9N2 virus in mammalian host by providing the data on mice lung immune responses to the avian H9N2 virus.