Objective To summarize the relationship between microRNA and the occurrence and progression of colorectal cancer， and to investigate the application value of microRNA in the diagnosis， treatment， and prognosis evaluation of colorectal cancer. Methods Domestic and international publications involving the relationship between microRNA and colorectal cancer were retrieved and reviewed. Results MicroRNA acted as an oncogene or tumor suppressor gene to participate in cell proliferation， differentiation， apoptosis， metabolism， tumor genesis， and tumor progression. The abnormal expression of microRNA was closely related to the occurrence and progression of colorectal cancer. As specific biomarker， microRNA could be applied in early diagnosis， chemotherapy strategy-making， and prognostic evaluation of colorectal cancer. Conclusion MicroRNA is definitely related to the occurrence and progression of colorectal cancer， and it has great prospect in the basic research and clinical applications of colorectal cancer.