微小RNA(microRNA, miRNA)是一类长度为18~25个核苷酸组成的内源性非编码小分子RNA，miRNA主要通过与靶基因序列特异性翻译抑制的相互作用在转录后水平对基因表达进行调节，从而参与多种生物学功能。与肿瘤细胞的增殖，凋亡等过程密切相关。在肿瘤的早期诊断和治疗中发挥了重要的作用。它们可以作为肿瘤诊断的潜在的生物标志物。本文就微小RNA(microRNA, miRNA)在消化道肿瘤中的生物学意义及进展做出综述。 miRNAs are a group of endogenous non-coding small RNA molecules of 18 - 25 nt. They regulate gene expression at the posttranscriptional level through interaction with inhibition of target gene translation, involving in a variety of important biological processes. They link closely to the proliferation and apoptosis of the tumor cell and play a very important role in the early diagnosis and therapeutic. They can be regarded as a promising biomarker of carcinoma. This review tries to do a short introduction of the research progresses and biological significances of miRNA in digestive neoplasms.