Abstract: Objective: To investigate the relationship between the distribution and quantity of memory T lymphocytes, dendritic cells (DCs) and cytotoxic T lymphocytes in the tumor microenvironment and the prognosis of gastric carcinoma. Methods:Immunohistochemistry was used to assess the densities of CD45RO+, CD11c+ and CD 8 + cells in the tumor mi-croenvironment of60gastric cancer cases. These densities were evaluated for associations with clinicopathologic charac -teristics and survival. Results: The density of memory T lymphocytes, dendritic cells (DCs) and cytotoxic T lymphocytes in the tumor microenvironment was negatively correlated with regional lymph node metastasis. Kaplan-Meier survival analysis revealed that patients in the high-density groups for CD45RO+T, CD 11c+ (DCs), CD8 + T and CD45RO+TCD11c+ (DCs) CD8 + T had a significantly longer survival time than those in the corresponding low-density groups. Furthermore lymphatic metastasis, TNM stage and diameter of the primary tumor were correlated with the prognosis. In multivariate survival analy-sis, the density of CD 45RO+ T cells and lymph node metastasis remained independent prognostic factors with hazard ra-tios (95% CI) of 0.437 (0.192 -0.992 ) and 2.330 (1.136 -4.779 ), respectively. Conclusion: Immunocyte density is predictive of lymph node metastasis. The density of CD 45RO+T cells can be used as an independent prognostic factor.