MicroRNA-145（miR-145） is considered to play key roles in many cellular processes,such as proliferation, differentiation and apoptosis, by inhibiting target gene expression.The transcriptional regulation of cardiovascular development requires precisespatiotemporal control of gene expression. We are beginning to understand the functions of miRNA145play during essentialbiological processes especially erythropoiesis. Here, we overview the recent findings onmiRNA145regulation in erythropoisis development and report the latest advances inunderstanding their function by unveiling their mRNA targets. Further analysis of miRNAfunction during erythropoisis development will allow us to determine the potential fornovel miRNA145-based therapeutic strategies. In this study we are trying to study the miRNA-145participates in the regulation ofthe early stages of erythropoiesis and if the mir-145is expressed during Zebra fish earlydevelopmental stages and we try to find the relationship between the Meis1and show howmir-145represses erythroid cell cycle progression by targeting meis1and find out if theMeis1is one of the mir-145targets. Enforced expression of miRNA-145in zebra fishcaused significantly decreased and limitation erythropoiesis and myeloid expansion. Onthe contrary, miRNA-145knockdown embryos had significantly fewer myeloid progenitorcells and expanded erythroid progenitor cells. These results indicate that miRNA-145is anewly identified evolutionarily conserved molecule which is essential for thedetermination of myelo-erythroid progenitor cell fate in vivo.