Objective To observe the diagnosis value of serum pepsinogen Ⅰ (PG Ⅰ),gastrin-17 (G-17),soluble human leukocyte antigen (sHLA-G) detection in gastric cancer.Methods Ninety-four cases of newly diagnosed patients with gastric cancer were selected as treatment group Ⅰ,31 patients were divided into stage Ⅰ-Ⅱ and 63 patients with stage Ⅲ-Ⅳ according to TNM stage,another 37 cases of chronic atrophic gastritis patients as treatment group Ⅱ,44 cases of gastric intraepithelial neoplasia patients as treatment group Ⅲ,50 cases of healthy people as control group.The expression levels of serum PG Ⅰ were detected by chemiluminescence immunoassay,serum G-17 and plasma sHLA-G levels were detected by enzyme-linked immunosorbent assay,accorded to the PG Ⅰ,G-17,sHLA-G expression level to draw the receiver operating characteristic (ROC) curve,and the ROC curve of each index were analyzed.Results The peripheral blood PG Ⅰ of treatment Ⅰ,Ⅱ,Ⅲ groups and control group were (52.78 ± 8.14),(65.79 ± 9.07),(66.34 ± 9.15),(76.69±10.31)mg· L-1,G-17 were (9.87 ±0.76),(4.69 ±0.40),(4.69 ±0.40),(3.43±0.21) pmol · L-1,sHLA-G were (83.63 ± 13.29),(56.83 ± 8.58),(54.95 ± 8.37),(37.24 ± 5.91) U · mL-1,had significant difference compared with control group (P ＜ 0.05).The peripheral blood of PG Ⅰ in Ⅰ-Ⅱ group [(58.71 ±7.49)mg · L-1] was significantly higher than Ⅲ-Ⅳ group [(49.55 ± 6.42) mg · L-1].G-17 [(8.97 ± 0.67) pmol · L-1] and sHLA-G [(74.29 ± 8.94) U · mL-1] in Ⅰ-Ⅱ group were significantly lower than Ⅲ-Ⅳ group [(10.33 ± 0.84) pmol · L-1,(88.39 ± 10.38) U · mL-1] (P ＜ 0.05).Diagnosis of gastric cancer AUC in PG Ⅰ,G-17,sHLA-G were 0.792,0.692,0.853,AUC of sHLA-G significantly higher than PG Ⅰ and G-17 (P ＜0.05),PG Ⅰ AUC significantly higher than G-17 (P ＜0.05).The specificity(92.5％) and positive predictive value(88.9％) of sHLA-G were the highest,and the sensitivity(84.7％) and negative predictive value(81.8％) of PG Ⅰ were the highest.Conclusion PG Ⅰ significantly decrease in peripheral blood of patients with gastric cancer,G-17,sHLA-G significantly increase,PG Ⅰ,G-17,sHLA-G can be used as an effective complement for the diagnosis of gastric cancer.