Epigenetics indicates the heritable changes in gene expression without nucleotide sequence variation. Leukemogenesis is closely related to abnormal epigenetic regulation. MicroRNA is a non-coding microRNA which regulates the expression of target mRNAs at both transcriptional and translational levels. MicroRNA plays a key role in leukemogenesis when being expressed abnormally in blood cells. MicroRNA in the field of epigenetics became a new hot topic of research on abnormal epigenetic regulation in leukemia genesis. In this article, the abnormal epigenetic regulation and leukemogenesis, the role of miRNA abnormal expression in leukemogenesis, the useful perspective of miRNA in diagnosis, classification, therapy and assessment of leukemias are reviewed.