Micro RNAs, small non-coded RNA of about 18–25 nucleotides, regulate target genes expression by partially complementary binding to 3′UTRs(untranslated regions) and are involved in many biological processes.Recently, microRNAs have been studied broadly in teleosts. This paper briefly reviews the biological property of microRNAs and the post-transcriptional regulation they confer, focusing on microRNAs expression pattern and the discovery of microRNAs in teleost fish by next-generation sequencing. The functio...