Abstract: Interferon gamma (IFN-_γ) is a major immunomodulatory factor in mammals. IFN-_γmediates its effects by binding a tetrameric receptor complex which is comprises of two IFN-_γ receptor (IFNGR) 1 chains and two IFNGR2 chains. Two isoforms of IFNGR1, cytokine receptor family member B (CRFB) 13 and CRFB17, have been isolated from some teleost fish. In this study, a CRFB13 homologue ( LycCRFB13 ) was identified and characterized in large yellow croaker ( Larimichthys crocea ). The open reading frame (ORF) of LycCRFB13 is 1 158 bp, encoding a protein consisting of 385 amino acids. The deduced LycCRFB13 protein exhibits a typical domain architecture of type II cytokine receptors, including a signal peptide, an extracellular FN III-like domain, a transmembrane region and intracellular JAK1 and STAT1 docking sites. Amino acid sequences alignment also revealed that all fish CRFB13 have potential JAK1 and STAT1 docking sites. Phylogenetic analysis showed that LycCRFB13 is closely related to CRFB13 of damselfish ( Stegastes partitus ) and falls into a clade formed by all fish CRFB13 sequences, separated from CRFB17 clade. LycCRFB13 mRNA was constitutively expressed in all tissues tested, with higher expression level in gills and lower in intestine. The transcription levels of LycCRFB13 mRNA were significantly up regulated in gills and head kidney after stimulated by poly(I:C). Moreover, both LPS and poly(I:C) also could induce expression of LycCRFB13 in head kidney Leukocytes of large yellow croaker. In all, the results indicate that LycCRFB13 may play roles in antiviral and antibacterial immune responses in large yellow croaker.