Objective To observe the expression of programmed death ligand 1 (PD-L1) in gastric adenocarcinoma in Zang nationality and investigate its correlation with the clinicopathological characteristics of patients. Methods A total of 60 cases of pathologically confirmed gastric adenocarcinoma were collected from January 2020 to December 2022. The immunohistochemical expression of PD-L1 (22C3) was evaluated according to the combined positive score (CPS) protocol. CPS 5 was used as PD-L1 positive standard. Results The 60 patients were all Zang nationality, including male (71.7%) and female (28.3%); the median age was 64 years; gastric antrum (40.0%) and gastric body (31.7%); histological grade was mostly poorly differentiated adenocarcinoma (71.7%); histological subtype was low-adhesive carcinoma (56.7%). In this study, the positive rate of PD-L1 was 45.0%, and the high expression of PD-L1 was significantly associated with patient age (P=0.013) and histological subtype (P=0.025), and less associated with factors such as sex, tumor site(P>0.05).The HP infection rate in this group of cases was 63.3% (38/60), and the PD-L1 positivity rate of HP positive patients was significantly higher than that of negative patients (P=0.007). The objective remission rate (44.4% vs 18.2%) and survival time of PD-L1 positive patients were significantly better than those of the negative group (median PFS 8.2 vs 5.1 months, P=0.032); 1 year OS 66.7% vs 39.4%, P=0.032）. Conclusion The incidence of gastric cancer in Xizang is high, and most of gastric adenocarcinoma has been advanced, with poor prognosis. The results of this study showed that the PD-L1 expression rate of gastric adenocarcinoma in Xizang area is about 45%. Exploring PD-L1 expression in gastric adenocarcinoma will provide the basis for identifying gastric cancer patients who may benefit from anti-PD-1/PD-L1 therapy