MiRNAs are small non-coding single stranded RNAs that play crucial roles in numerous biological processes. Vertebrate herpesviruses encode multiple viral miRNAs that modulate host and viral genes. However, the roles of viral miRNAs in invertebrates have not been fully determined. Here, we used high-throughput sequencing to analyse miRNA and mRNA expression pro?les of Carassius auratus gibelio in response to infection by cyprinid herpesvirus 2 (CyHV-2). RNA sequencing obtained 26,664 assembled transcripts, including 2,978 differentially expressed genes, among which 12 were validated by qRT-PCR. Based on small RNA (sRNA) sequencing and secondary structure predictions, we identified 17 CyHV-2 encoded miRNAs. Target prediction for the viral miRNAs identi?ed >1,109 host and virus gene target pairs. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analysis of the viral miRNAs revealed diverse affected immune signalling pathways, including the RIG-I-like receptor, the Toll-like receptor and the JAK-STAT signalling pathways. Finally, we presented a functional analysis of CyHV-2-encoded ORF60 and host gene TLR5, both of which are targeted by CyHV-2 miRNA miR-C1. Overall design: Collectively, The present study is the first to provide a comprehensive overview of viral miRNA-mRNA co-regulation, which might have a key role in controlling post-transcriptomic regulation during CyHV-2 infection.