Abstract: MicroRNAs (miRNAs) are endogenous, non-coding, single-strand RNA molecules with a length of about 22-nucleotides (nt). They have post-transcriptional control of the expression of various target genes. Previous research con -firmed that miRNAs play an important role in regulating cell proliferation, development, differentiation, apoptosis, metabo -lism and signal transduction, as well as oncogenesis. Research also confirmed that miRNAs could inhibit the expression of oncogenes or anti-oncogenes, and could take part in the tumorigenesis and progression of gastrointestinal cancers. In our paper, the effect of miRNAs in human gastrointestinal cancers is summarized.