中文摘要：

微小RNA（miRNA）是一类内源性、长约22nt的非编码单链RNA分子，通过与靶mRNA特异性的结合导致靶mRNA降解或抑制其翻译，对基因进行转录后调控。本文就microRNA在干细胞中的表达特点及其作用、microRNA在干细胞向成骨定向分化扮演的角色以及microRNA成骨细胞增殖分化过程中的调控机制等方面的进展予以综述。

英文摘要：

A class of single-stranded non-coding RNA, known as ＂ microRNAs＂, regulates translation process, by binding to target mRNAs to degrade mRNAs or inhibit translation. Therefore, they can participate in post-transcriptional regulation. This paper reviewed the expression of microRNA in stem cell and their functions, the roles of microRNA during osteogenetic differentiation and proliferations of osteoblast.