〔Abstract〕 Objective To analyze the current status of anti-PD-1 combined with chemotherapy in advanced gastric cancer. Methods The clinical data of 120 patients with advanced gastric cancer treated with chemotherapy or anti-PD-1 plus chemotherapy were retrospectively analyzed. The efficacy [measures include objective response rate(ORR), disease control rate(DCR), and progression-free survival(PFS)]and the occurrence of adverse reactions in patients was monitored. Univariate and multivariate Cox were used to analyze the relationship between clinicopathologic data [including age, gender, body mass index(BMI), differentiation degree, and related hematological indexes], specific treatment conditions and PFS, and to analyze the influence of treatment plan and line number on the curative effect. Results The PFS of chemotherapy plus immunotherapy was significantly better than that of chemotherapy alone(P<0.05), and the median PFS of the two was 7.17 months(95%CI5.85-8.49) and 5.33 months(95%CI3.96-5.70), respectively. In the combination group, the overall ORR was 27.5% and DCR was 94.8%. In the chemotherapy group alone, the overall ORR was 9.7% and DCR was 69.4%.In the chemotherapy plus anti-PD-1 group, a high prognostic nutritional index(PNI) level also provided superior PFS in patients with a 47% reduction in the risk of progression versus a low PNI level [HR0.53(95%CI0.30-0.96);P<0.05]. The median PFS was 7.47 months(95%CI5.83-9.11) with a high PNI level versus 6.00 months(95%CI4.45-7.55) with a low PNI level. The overall incidence of adverse reactions of chemotherapy combined with anti-PD-1 was slightly higher than that of chemotherapy alone, and the incidence of adverse reactions of grade 3-4 was similar, within a controllable range, and could be improved after clinical treatment. Conclusion The efficacy of anti-PD-1 combined with chemotherapy in patients with advanced gastric cancer is better than that of chemotherapy, and the adverse reactions are controllable. In the chemotherapy plus anti-PD-1 group, patients with high PNI levels achieved a higher PFS.