Objectives: Endometrial cancer is the most common gynecologic malignancy in the United States with an expected 65620 new cases and 12590 deaths in 2020. Currently, lymph node status is based on the presence of lymph node metastases regardless the number of resected lymph nodes. However, this may not accurately assess the true nodal burden of disease. Recently, the log of odds between positive lymph nodes and the number of negative lymph nodes (LODDS) has emerged as an alternative predictive factor of outcomes in ovarian, cervical, and colorectal cancers. Its utility for endometrial cancer is unknown. This study aims to establish the effective and prognostic value of LODDS in predicting the survival of endometrial cancer (EC) patients undergoing surgical resection Methods: This is a retrospective study using the SEER database consisting of 18 population-based cancer registries. We calculated LODDS, using the equation log[(pLN+0.5)/(nLN+0.5)], where pLN=# of positive lymph nodes, nLN=# of negative lymph nodes, and 0.5 is added to both pLN and nLN to eliminate the possible production of an infinite value. We compared LODDS and FIGO stage using Kaplan-Meier analysis, and the univariate Cox regression model to analyze the risk factors for survival outcome. We also evaluated the the independent prognostic effect of the variables identified from the uni-variate Cox model using with the multivariate Cox regression model. LODDS was a continuous variable in the model. We performed data analysis with SAS, and all statistical tests were two-sided with α =.05. Results: The analysis included 3230 EC patients from the SEER database (FIGO Stage IIIC1 = 1546, FIGO Stage IIIC2 = 958, FIGO Stage IV = 726). Most cases (58.02%) were of high-grade histology (FIGO Grade 3-4). 59.01% were classified as Type II EC. There were 925 endome-trial cancer-specific deaths. Patients were categorized into two groups: LODDS < -0.12707, and LODDS ≥ - 0.12707 based on results from results of C-statistics and ROC curves comparing various lymph node measures and prediction of disease specific survival (DSS), where LODDS predicted DSS better. Kaplan-Meier curve analyses showed 1-, 3-, and 5-year DSS rates. These values were 93.9, 75.9, and 67.5% for LODDS < -0.12707, and 78.6, 49.6, and 38.1% for LODDS ≥ - 0.12707, respectively. Cumulative 1-, 3-, and 5-year DSS were 91.0, 71.1, and 62.2%, respectively. In multivariate analysis, LODDS is an independent prognostic factor for EC mortality (HR = 2.138, 95% CI 1.849-2.473, P<0.0001). Conclusions: LODDS classification has significant prognostic value for survival among patients with endometrial cancer. Endometrial cancer is the most common gynecologic malignancy in the United States with an expected 65620 new cases and 12590 deaths in 2020. Currently, lymph node status is based on the presence of lymph node metastases regardless the number of resected lymph nodes. However, this may not accurately assess the true nodal burden of disease. Recently, the log of odds between positive lymph nodes and the number of negative lymph nodes (LODDS) has emerged as an alternative predictive factor of outcomes in ovarian, cervical, and colorectal cancers. Its utility for endometrial cancer is unknown. This study aims to establish the effective and prognostic value of LODDS in predicting the survival of endometrial cancer (EC) patients undergoing surgical resection This is a retrospective study using the SEER database consisting of 18 population-based cancer registries. We calculated LODDS, using the equation log[(pLN+0.5)/(nLN+0.5)], where pLN=# of positive lymph nodes, nLN=# of negative lymph nodes, and 0.5 is added to both pLN and nLN to eliminate the possible production of an infinite value. We compared LODDS and FIGO stage using Kaplan-Meier analysis, and the univariate Cox regression model to analyze the risk factors for survival outcome. We also evaluated the the independent prognostic effect of the variables identified from the uni-variate Cox model using with the multivariate Cox regression model. LODDS was a continuous variable in the model. We performed data analysis with SAS, and all statistical tests were two-sided with α =.05. The analysis included 3230 EC patients from the SEER database (FIGO Stage IIIC1 = 1546, FIGO Stage IIIC2 = 958, FIGO Stage IV = 726). Most cases (58.02%) were of high-grade histology (FIGO Grade 3-4). 59.01% were classified as Type II EC. There were 925 endome-trial cancer-specific deaths. Patients were categorized into two groups: LODDS < -0.12707, and LODDS ≥ - 0.12707 based on results from results of C-statistics and ROC curves comparing various lymph node measures and prediction of disease specific survival (DSS), where LODDS predicted DSS better. Kaplan-Meier curve analyses showed 1-, 3-, and 5-year DSS rates. These values were 93.9, 75.9, and 67.5% for LODDS < -0.12707, and 78.6, 49.6, and 38.1% for LODDS ≥ - 0.12707, respectively. Cumulative 1-, 3-, and 5-year DSS were 91.0, 71.1, and 62.2%, respectively. In multivariate analysis, LODDS is an independent prognostic factor for EC mortality (HR = 2.138, 95% CI 1.849-2.473, P<0.0001). LODDS classification has significant prognostic value for survival among patients with endometrial cancer.