Objective:To investigate the predictive value of preoperative peripheral blood lymphocyte to monocyte ratio (LMR) for lymph node metastasis in gastric cancer.Methods:Data of 177 gastric cancer patients who underwent surgical treatment in Beijing Shijitan Hospital from Jan 2014 to May 2017 were retrospectively analyzed. According to the ROC curve, the optimal critical value is determined to be 3.79. By this value, patients were divided into high LMR group (LMR≥3.79) and low LMR group (LMR<3.79). Patients′ clinicopathological characteristics were collected to analyze the relationship between LMR and lymph node metastasis and lymph node N staging.Results:A comparison of LMR and N1 and N2 stage between the two groups showed no significant difference, but both N1 and N2 had statistical defference with N3 ( P<0.05), suggesting a positive correlation between low LMR and high N stage. Logistic regression analysis proves that low LMR is significantly correlated with metastatic lymph node when the number was more than 6. Conclusion:Low LMR is positively correlated with lymph node metastasis in gastric cancer patients.