Abstract: MicroRNA is a type of endogenous noncoding small molecular RNA with a length of 19-25nucleotides. MicroRNAs are involved in almost all key biological processes, such as cell proliferation, differentiation, apoptosis, and hematopoiesis, via repres -sion of target gene expression. Acute lymphoblastic leukemia (ALL) is the most common type of pediatric cancer. It is a heterogeneous disease with different clinical signs, morphology, immunophenotype, and cytogenetics. Currently, several microRNAs have implicated aberrant expression in ALL and play an important role in cancer initiation and development. MicroRNA expression pattern is associated with clinical feature, prognosis, and treatment. Therefore, microRNAs could act as a novel marker to help scientists learn about the pathogenesis of ALL and to provide more effective treatment options.