Abstract: The interferon-induced transmembrane (IFITM)proteins usually protect cells from a variety of viruses by inhibiting their entry into them.In order to identify whether the H5N1 virus itself and structural proteins act as a new regulator of IFITM gene,it investigates the effect of H5N1 virus and structural proteins on IFITM gene family transcription through experiments.The results show that the NS1,M1,NP and PB2 proteins of H5N1 virus increases the expressions of IFITM1,IFITM2 and IFITM3 in A549 cell,and has no effect on HEK293T cell.No HA and NA proteins of H5N1 virus were found to affect the IFITM gene family expression in HEK293T cell and A549 cell.That is,during the infection of H5N1 avian influenza virus,the overexpression of NS1,M1,NP and PB2 protein can directly stimulate the up-regulation of IFITM1,IFITM2 and IFITM3.While the respiratory epithelial cells may be affected first,in particular,NP and NS1 showed a more significant effect on the IFITM gene family expression.