MicroRNAs (miRNAs) are small non-coding RNAs that contribute to the repertoire of host-pathogen interactions during viral infections. In the current study， miRNA analysis showed that a panel of microRNAs， including gga-miR-9*， were markedly upregulated in specific-pathogen-free (SPF) chickens upon infection with infectious bursal disease virus (IBDV); however， the biological function of gga-miR-9* during viral infection remains unknown. Using a TCID50 assay， it was found that ectopic expression of gga-miR-9* significantly promoted IBDV replication. In turn， gga-miR-9* negatively regulated IBDV-triggered type I IFN production， thus promoting IBDV replication in DF-1 cells. Bioinformatics analysis indicates that the 3' untranslated region (UTR) of interferon regulatory factor 2 (IRF2) has two putative binding sites for gga-miR-9*. Targeting of IRF2 3'UTR by gga-miR-9* was determined by luciferase assay. Functional overexpression of gga-miR-9*， using gga-miR-9* mimics， inhibited IRF2 mRNA and protein expression. Transfection of the gga-miR-9* inhibitor abolished the suppression of IRF2 protein expression. Furthermore， IRF2 knockdown mediated the enhancing effect of gga-miR-9* on the type I IFN-mediated antiviral response. These findings indicate that inducible gga-miR-9* feedback negatively regulates the host antiviral innate immune response by suppressing type I IFN production via targeting IRF2.