Abstract: Objective :To study the local immune and its immune escape status in gastric cancer by detecting the mRAN and protein expressions about 4-1BBL and IL-18 in gastric cancer, gastric mucosa, greater omentum, small omentum, peritoneum and draining lymph nodes tissues. Methods :The mRNA expressions of 4-1BBL and IL-18 were examined by reverse transcript polymerase chain reaction and the protein expressions of 4-1BBL and IL-18 were detected by flow cytometry in the human tissues of gastric cancer, gastric mucosa, greater omentum, small omentum, peritoneum and drainning lymph nodes. Results :The expressions of 4-1BBL and IL-18 have been detected in the tissues of gastric cancer, gastric mucosa, greater omentum, small omentum, peritoneum and drainning lymph nodes and these expressions in gastric cancer were higher than those of other tissues (P<0.05). Conclusion :The immune status is low in gastric cancer tissue and it can be conjectured that this phenomenon relates to the deficiency of 4-1BBL and IL-18.