Colorectal Cancer (CRC) is one of the most common malignant tumors of gastrointestinal tract. The occurrence, development, diagnosis and prognosis have become a hot topic in current clinical research. However, current diagnosis and treatment still depend on the results of tumor imaging or pathology test. Therefore, to reveal the biological pathogenesis of CRC and to discover specific biomarkers for early diagnosis and better prognosis assessment of CRC have become key roles in current studies. Recent literature has revealed that aberrant expression of microRNAs (miRNAs) could contribute to the development and progression of CRC through the regulation of several critical pathways, including apoptosis, epithelial-mesenchymal transition, angiogenesis and signal transduction. These findings have also indicated that miRNAs could be a novel biomarker for early clinical diagnosis and prognosis evaluation of CRC. In this review, we have summarized the recent studies of miRNAs on the diagnosis, treatment and prognosis clinical biomarker of CRC. We also discussed the regulatory mechanisms of miRNAs in CRC, which may guide the future treatment for CRC.