Objective To investigate the expression of human epidermal growth factor receptor 2(HER2),carbohydrate antigen 199(CA199)and microtubule-associated protein 1 light chain 3β(LC3B)in gastric canc-er tissues and their relationship with recurrence after radical gastrectomy.Methods A total of 95 patients with gastric cancer who underwent radical gastrectomy in the hospital from January 2021 to December 2022 were retrospectively selected.The expressions of HER2,CA199 and LC3B in gastric cancer tissues and adja-cent tissues were compared,and the clinicopathological characteristics were analyzed.According to the postop-erative recurrence of gastric cancer patients,they were divided into recurrence group(n=19)and non-recur-rence group(n=76).Univariate analysis and multivariate Logistic regression analysis were used to analyze the influencing factors of recurrence in patients with gastric cancer after radical resection.Results The ex-pression levels of HER2,CA199 and LC3B in gastric cancer tissues were significantly higher than those in pa-racancerous tissues(P<0.05).The positive expression rates of HER2,CA199 and LC3B in gastric cancer tis-sues(38.95%,38.95%and 35.79%,respectively)were higher than those in adjacent tissues(9.47%,7.37%and 11.58%,respectively),and the differences were statistically significant(P<0.05).The positive expres-sion rate of HER2 in gastric cancer tissues was significantly different in patients with different TNM stage and lymph node metastasis(P<0.05).There were significant differences in the positive expression rates of CA199 and LC3B in gastric cancer patients with different tumor maximum diameter,TNM stage and lymph node metastasis(P<0.05).The maximum diameter of tumor≥5 cm,TNM stage Ⅲ/Ⅳ,lymph node metas-tasis,positive expression of HER2,positive expression of CA199 and positive expression of LC3B were inde-pendent risk factors for recurrence of gastric cancer patients after radical resection(P<0.05).Conclusion The gene expression and positive expression rates of HER2,CA199 and LC3B in gastric cancer tissues are high,which are related to the maximum tumor diameter,TNM stage and lymph node metastasis.The positive expression of HER2,CA199 and LC3B may increase the risk of recurrence of gastric cancer after radical gastrectomy.