Abstract: Objective: To evaluate the value of short-to-long-diameter ratio(SLR) combined with relative enhancement in the diagnosis of lymph node metastasis of colon cancer. Methods: 47 cases of colon cancer diagnosed by surgery in our hospital were analyzed retrospectively. All patients underwent plain abdominal CT scan and enhanced CT scan. The parameters of short diameter, ratio of short to long diameter, CT value and relative enhancement value of abdominal suspicious lymph nodes were recorded. The results were compared with each other. ROC curve was drawn to analyze the diagnostic value of each parameter. Results: compared with non-metastatic lymph nodes, the value of short diameter, short-to-long diameter ratio, CT value of plain scan, arterial and venous phase and relative enhancement value of metastatic lymph nodes were significantly increased(P<0.01). The ROC curves were 0.649, 0.725, 0.713, 0.723, 0.696, 0.793 for short diameter, ratio of short to long diameter, CT value of plain scan, arterial and venous phase and relative enhanced value, respectively, the sensitivity was 63.30%, 76.70%, 73.30%, 60.00%, 76.72%, 73.30%, and the specificity was 75.00%, 70.00%, 60.00%, 65.00%, 90.00% respectively, the sensitivity and specificity were 86.70% and 85.00%, respectively. The Kappa Coefficient was 0.787. Conclusion: The short-to-long-diameter ratio(SLR) combined with the relative enhanced value of MSCT has high sensitivity to lymph node metastasis of colon cancer, which can provide important evidence for clinical diagnosis of lymph node metastasis.