Objective To study the effect of microRNA-183(miR-183)on the growth and development of ze-brafish inner ear,and its mechanism in the regeneration and growth of inner ear hair cells,otocyst and otolith in-jured by cisplatin.Methods Synthesized miRNAs(agomir)and antisense morpholino oligonucleotides(MOs)were injected into zebrafish embryos by microinjection to construct the model of these miRNAs'levels.The 72-hours post fertilization zebrafish were immersed in 50 μmol/L cisplatin for 24 hours.MiRNA microarray analysis,RT-qPCR and other techniques were used to detect the changes of miR-183 and FOXO1 gene expression.FM1-43FX fluores-cence staining was used to understand the injury and regeneration of inner ear nerve thalamic hair cells.The micro-scope was used to observe the growth and development of otocyst and otoliths.Results ① After the treatment of cisplatin,the inner ear hair cells of zebrafish were damaged and the growth and development of otocyst and otoliths were hindered.After the removal of cisplatin,the inner ear hair cells could be regenerated,and the growth and de-velopment of otocyst and otoliths also recovered gradually.② miR-183 was activated after the removal of cisplatin,which was one of the most differentially expressed members in zebrafish larva miRNA(P＜0.001),and the expres-sion level increased continuously to the peak and then gradually returned to the normal level.③ Compared with the control group,after the removal of cisplatin,the overexpression of miR-183 could promote the recovery of the num-ber of hair cells and the area of otocyst and otoliths,while the recovery was inhibited in the group with low expres-sion of miR-183.④ After the removal of cisplatin,FOXO1 was activated and the expression was up-regulated(P＜0.01).When miR-183 was overexpressed,FOXO1 was inhibited and expression was down-regulated(P＜0.01).Conversely,when miR-183 was low,the expression of FOXO1 increased(P＜0.01).Conclusion The increase of miR-183 expression occurs simultaneously with the regeneration of inner ear hair cells and the recovery of growth and development of the otolith area after cisplatin removal.The overexpression or low expression of miR-183 can promote or inhibit the regeneration of inner ear hair cells and the recovery of growth and development of the otolith area,indicating that there is a positive regulatory relationship between them.The mechanism may be related to the negative regulation of miR-183 on FOXO1.