〔Abstract〕 Objective To investigate the clinical value of coefficient of variation(RDW-CV) and standard deviation(RDW-SD) of erythrocyte distribution width in the diagnosis of colorectal cancer(CRC) metastasis. Methods 91 CRC inpatients were selected as the research subjects. According to whether the tumor was metastatic, they were divided into two groups: 61 cases in the non-metastatic group and 30 cases in the metastasis group. The laboratory indicators of the two groups of patients included: neutrophils count, lymphocyte count, platelet count, carcinoembryonic antigen, plasma prothrombin time, activated partial thromboplastin time, fibrinogen, thrombin time, RDW-CV and RDW-SD and other indicators. Thettest was used to compare the means of the two groups, and the pearson correlation was used to analyze the relationship between RDW-CV and RDW-SD with neutrophil count, lymphocyte count, neutrophil count-lymphocyte count ratio(NLR) and carcinoembryonic antigen. Correlation coefficient, receiver operating characteristic curve(ROC) to assess the area under the curve(AUC) of RDW-CV, RDW-SD, carcinoembryonic antigen and their combined diagnosis in assessing CRC metastasis. Results Compared with non-metastatic patients, the RDW-CV and RDW-SD values of metastatic patients were higher(bothP<0.05). Both RDW-CV and RDW-SD levels were positively correlated with carcinoembryonic antigen content. Compared with the AUC of carcinoembryonic antigen in diagnosis of CRC metastasis, the AUC of RDW-CV or RDW-SD combined with carcinoembryonic antigen was higher. Conclusion RDW-CV and RDW-SD have potential clinical application value in differential diagnosis of CRC metastasis.