ObjectiveTo summarize the current research progress of serum exosome microRNAs in patients with colorectal cancer.MethodsThe domestic and foreign literatures related to serum exosome microRNAs of colorectal cancer patients, which had been reported in recent years were collected through literature search. Subsequently, those literatures were used to read and review.ResultsExosomes were extracellular vesicles, which contained lipids, proteins, DNA, RNA (mRNA, microRNA, and long non-coding RNA), and other molecules. These vesicles mediated communication between cells by transporting the above molecules. Exosomes in serum were the main carriers of microRNAs in the blood circulation system. Serum exosome microRNAs could affect the proliferation, invasion, and metastasis of colorectal cancer cells, mediate the drug resistance of colorectal cancer cells, and could be used as biomarkers to predict the prognosis of colorectal cancer.ConclusionsSerum exosome microRNAs play important role in the occurrence, development, treatment, and diagnosis of colorectal cancer. As a class of biomarker, serum exosome microRNAs have great potential in the early diagnosis and prognostic evaluation of colorectal cancer.