Abstract: Objective To assess the expression of Ki-67 in gastroenteropancreatic neuroendocrine tumors（GEP-NETs） and analyze the relationship between TNM stage， pathological grading and prognosis. Methods The clinicopathological features of 110 patients with GEP-NETs treated in the first Affiliated Hospital of Nanjing Medical University from January 2005 to December 2010 were retrospectively reviewed. The expression of Ki-67 in tumor specimens was detected by immunohistochemistry method. According to Ki-67 proliferation index， the pathological grading was carried including G1， G2 and G3.The mortality rate， median overall survival （mOS）， 2-year survival rate and the risk for death of different TNM stages and histological grades were analyzed. Results Seventy-eight patients were available for follow-up. The mortality rate of patients with stage Ⅰ， Ⅱ， Ⅲ and Ⅳ were 8.7％， 11.5％， 36.0％ and 75.0％； mOS were 68.0， 49.0，39.0 and 24.0 months； 2-year survival rates were 91.7％， 85.7％， 61.9％ and 50.0％. The mortality rate of patients with G1， G2 and G3 were 9.4％， 50.0％ and 55.6％； mOS were 73.0， 28.0 and 28.0 months； 2-year survival rates were 91.7％， 42.9％ and 50.0％.There were significant differences among different TNM stages and pathological grades on mOS and 2-year survival rate （P＜0.01）. The risks of death of stage Ⅲ and stage Ⅳ increased relative to stage Ⅰ（P＜0.05）， as well as G2 and G3 relative to G1（P＜0.01）. Conclusion The GEP-NETs with later TNM stage or higher Ki-67 proliferation index showed worse prognosis.