Objective To investigate the value of platelet/lymphocyte ratio(PLR)in predicting death within 1 year in patients with advanced colon cancer undergoing chemotherapy.Methods A total of 166 patients diagnosed with advanced colon cancer were selected from March 2021 to March 2023 in Jilin City Central Hospital.During 1-year follow-up,72 patients died(death group)and 94 survived(survival group).The clinicopathological data and the levels of PLR,carcinoembryonic antigen(CEA),carbohydrate antigen(CA)199,CA724 and CA153 were compared between two groups.The influencing factors of death within 1 year in patients with advanced colon cancer were analyzed by multivariate Logistic regression.Receiver operating characteristic(ROC)curve evaluated the predictive value of PLR for death within 1 year in patients with advanced colon cancer.Results The mortality rate within 1 year was 43.37％.Compared with survival group,there was no statistically significant difference in gender,age,tumor node metastasis classification stage,location of colon,number of chemotherapy courses,and cancer history in death group(P＞0.05),but there were differences in diabetes history,smoking history,PLR,CEA,CA199,CA724 and CA153 levels in death group(P＜0.05).Multivariate Logistic regression analysis showed that PLR(OR=1.056,95％CI:1.000-1.116),CEA(OR=20.122,95％CI:2.602-155.617),CA199(OR=1.227,95％CI:1.069-1.408),CA724(OR=1.864,95％CI:1.174-2.962)and CA153(OR=1.741,95％CI:1.108-2.737)levels were risk factors for death within 1 year in patients with advanced colon cancer undergoing chemotherapy(P＜0.05).The ROC curve showed that the area under the curve of PLR level predicting death within 1 year in patients with advanced colon cancer chemotherapy was 0.79,and the sensitivity and specificity were 52.78％and 95.74％,respectively.Conclusion The level of PLR in patients who died within 1 year of chemotherapy for advanced colon cancer was significantly higher than that in patients who survived.PLR levels have reference value in assessing death within 1 year of chemotherapy for advanced colon cancer.