Abstract: Objective To investigate the expression difference and clinical significances of microRNA-371-5p in serum of patients with colorectal cancer. Methods The expression levels of microRNA-371-5p in the plasma of 50 colorectal cancer patients and 40 healthy controls were detected by qRT-PCR,and its correlation with clinical pathological parameters was analyzed.Receiver operating characteristic curve (ROC) analysis and the area under curve (AUC) was performed to estimate the diagnostic value of tumor markers. Results The expression level of microRNA-371-5p in colorectal cancer plasma (3.03±0.55) was significantly lower than that in the in serum of healthy people (3.98±0.47),t=-4.93,P<0.05.The expression level of microRNA-371-5p in colorectal cancer plasma was well correlated with the TNM stages and the metastasis of lymph node (P<0.05),but not with the age,gender and CEA level (P>0.05).AUC was 0.894,the specificity was 87%,and the sensitivity was 86%. Conclusion The microRNA-371-5p presents a low expression in the patients with colorectal cancer,so it might be involved in initiation and progression of colorectal cancer,thus it might be one of biomarkers of colorectal cancer.