microRNA (miRNA)是一类非编码小RNA分子，通过降解靶mRNA或抑制蛋白质翻译而在转录后水平上对基因表达进行负调控。近年来的大量研究表明，某些特异性miRNA在胚胎干细胞向心肌细胞分化的过程中发挥了不可替代的作用。此文阐述了miRNA的基本生物学特征，以及胚胎干细胞心肌分化及心脏发育过程中几种miRNA所发挥的作用。

microRNA (miRNA) is a class of non-coding small RNA molecules, which can negatively regulate the gene expression at post-transcriptional level by degrading the the target mRNA or inhibiting protein translation. In recent years, a large number of studies have shown that certain specific miRNAs played an irreplaceable role in the process of differentiation of embryonic stem cells to myocardial cells. This review describes the basic biological characteristics of miRNA, and summarizes the role of several miRNAs in the process of embryonic stem cell cardiac differentiation and heart development.