Objective To investigate the expression of serum miR-107 in patients with colorectal cancer and its diagnostic value for the disease.Methods 60 patients with colorectal cancer admitted to the hospital from January 2016 to January 2019 were enrolled as colorectal cancer group.60 patients with colorectal polyps treated in the hospital were selected as the polyp control group.60 healthy volunteers in the hospital were used as healthy controls.The relative expression of miR-107 was detected by real-time fluorescent quantitative PCR.The expressions of carcinoembryonic antigen(CEA),carbohydrate antigen 199(CA199)and miR-107 were compared between the three groups.The relationship between serum miR-107 and clinicopathological features of colorectal cancer patients was analyzed.Receiver operating characteristic(ROC)curve was used to analyze the diagnostic value of serum miR-107,CEA and CA199 for colorectal cancer.Results The relative expressions of serum miR-107 and serum CEA and CA199 levels in colorectal cancer group were higher than those in polyp control group and healthy control group,and the differences were statistically significant(P<0.05).The expression of serum miR-107 in colorectal cancer patients was not related to gender,age and tumor diameter(P>0.05),but was related to differentiation degree,TNM stage and lymph node metastasis(P<0.05).The area under the ROC curve obtained by miR-107 was 0.882(95%CI:0.814-0.950),and the sensitivity and specificity were 85.0%and 82.9%,respectively.When combined with CEA and CA199,the sensitivity and specificity can be increased to 91.7%and 86.7%.Conclusion miR-107 is highly expressed in the serum of patients with colorectal cancer.The expression level is related to the degree of differentiation,TNM stage and lymph node metastasis,and it has a high diagnostic value for colorectal cancer.