Abstract: Objective :To investigate the gastric cancer patient's local and entirety immunefunction by examining T cell subgroup and NIA cell in gastric cancer, gastric mucosa, lymph node, bigomentum, small omentum, peritoneum and blood. Methods : CD4⁺,CD8⁺T cell and NIA cell weredetected in gastric cancer, gastric mucosa, lymph node, big omentum, small omentum, peritoneum andblood of 40 gastric patients by flow cytometry. 22 benign patients gastric mucosa and blood were usedas control group. Results : The levels of CD4⁺, CD8⁺ T cell and NIA cell in gastric cancer and lymphnode were significantly higher than those of gastric mucosa, big omentum, small omentum, peritoneumand blood (P<0.05), but the ratio of CD4⁺/CD8⁺ in gastric cancer was lower than those of lymph nodeand big omentum (P<0.05). The levels of CD4⁺, CD8⁺T cell and NIA cell in the control group weresignificantly higher than those of gastric cancer patients. Conclusions : The local and entirety immunefunction in gastric cancer patient is lower than that of control group. The levels of CD4⁺, CD8⁺ T celland NIA cell in gastric cancer tissue are higher than those of gastric mucosa, big omentum, smallomentum and peritoneum, but the local immune function is low or suppressed.