Abstract: In this study, we obtained the full-length cDNA of grass carp Noxa (Cinoxa) and performed the sequence analysis and phynogenetic tree construction. Next we used quantitative PCR (qPCR) to explore the expression pattern of Noxa mRNA in response to GCRV infection. The results suggested that there was high similarity in the protein sequences between grass carp Noxa and zebrafish Noxa. The 3-demsional (3D) model analysis also revealed that their protein 3D models were identical, and the models were homologous with C-terminus of BCL-2 family in mammals. In response to GCRV infection, the expression of grass carp Noxa upregulated significantly in the kidney, spleen and head kidney and reached to the peak at 24h and 120h after infection. Our data indicated that the CiNoxa was ortholog of zNoxa in grass carp and was involved in the immune response to GCRV. This could provide fundamental information for the future study on functions of grass carp Noxa, and help understanding the mechanisms that regulate the transcription during GCRV infection.