MicroRNAs, 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 function studies about microRNA in teleost cover osmotic stress regulation, reproduction, development, growth, immunity, metabolism and other biological processes. Results show that miR-200 and miR-30 family members control the cellular ion balance and salt resistance. Dicer1 is essential to the development of zebrafish, its deletion is lethal and the organogenesis will be impaired. MiR-20a regulates the morphogenesis of head, eye, spinal cord, somite during the gastrula stage; miR-92 controls the formation of endoderm; miR-10 regulates the formation of body axis; miR-219 affects the apoptosis of head and tail, and miR-122, miR-30 and miR-145 respectively adjust maturation of liver cells, the development of liver and intestinal tract. The development of heart is under the control of miR-138 and miR-143; miR-126, miR-150, miR-451 regulate the development and maturation of thrombocytes and hemocytes; miR-10 and miR-126 regulate the formation of blood vessel; miR-200 and miR-183 each regulate the development of olfaction and auditory system. Multiple microRNAs are involved in the process of organ regeneration. MiR-133a/b and miR-206 inhibit the proliferation of myocyte; miR-214/499/199/3906 are involved in the process of quick-twitch and slow-twitch muscle differentiation; miR-430 promotes the generation of primordial germ cell, and microRNAs are also reported to be involved in multiple physiological processes of energy homeostasis, innate immunity, hypoxia adaptation, body color regulation, stress responses, intermuscular bone formation. This paper summarizes those results and will benefit the understanding of the present situation of the microRNAs research in teleost and may be helpful for the promotion of the study in noncoded RNA.