e15702 Background: To evaluate prognostic factors for patients with advanced gastric cancer treated by Third-line chemotherapy, and to identify the characteristics of long-term survivors. Methods: Eighty seven advanced gastric adenocarcinoma patients, who received third-line chemotherapy, were enrolled in this retrospective study from January 2010 until December 2014. Univariate and multivariate analyses were created using log-rank tests and Cox’s proportional hazard model, respectively. Results: In univariate and multivariate analyses, poor prognostic factor were investigated and four independent factors were found to be associated with poor overall survival: time-to progression under first-line chemotherapy≤6 months (HR, 1.64; 95% CI, 1.18–2.25; P ≤ 0.01), CA 19-9 level > 50 ng/ml (HR, 1.78; 95% CI, 1.32–2.67; P ≤0.007), the presence of ascites (HR, 1.67; 95% CI 1.295– 2.37, P ≤0.001), the presence of greater than or equal to three metastatic sites of disease (HR, 1.45; 95% CI 1.19– 2.19, P ≤0.004). 87 patients were classified as low-risk group( no risk factor), intermediate-risk group (one to two risk factors), high- risk group (three to four risk factor), and median survival times for each groups were 14.3 months, 12.1 months, and 7.4 months, respectively (P ≤0.01). Conclusions: This model will help in selecting the patients with advanced gastric cancer who could benefit from proceeding with third-line chemotherapy.