Abstract: OBJECTIVE To analyze the diagnostic value of CC chemokine ligand 20 (CCL20) in combination with carcinoembryonic antigen (CEA) and carbohydrate antigen (CA) 724 for Helicobacter pylori (Hp) infection related precancerous lesion of gastric cancer (PLGC). METHODS Totally 300 patients with chronic atrophic gastritis (CAG) complicated with Hp infection in the Department of Gastroenterology of Shanxi Fenyang hospital from Jan. 2020 to Dec. 2021 were selected as the study subjects, and were divided into the study group (CAG combined with PLGC, 81 cases) and the control group (CAG without PLGC, 219 cases) according to the presence or absence of PLGC. The clinical data and the levels of serum pepsinogen (PG) Ⅰ, PG Ⅱ, gastrin 17(G-17), CEA, CA724 and CCL20 at the time of admission in both groups were detected. The receiver operating characteristic (ROC) curve was employed to analyze the values of laboratory indicators for the diagnosis of PLGC. RESULTS The levels of serum PG Ⅰ and PG Ⅰ/ PG Ⅱ of the patients in the study group were lower than those in the control group (P<0.05). The levels of serum CEA, CA724 and CCL20 were higher than those in the control group (P<0.05). CEA, CA724 and CCL20 were the influencing factors of PLGC in Hp infected patients (P<0.001). ROC curve analysis showed that the areas under ROC curve (AUC) of serum CEA, CA724 and CCL20 levels for the diagnosis of PLGC were 0.756, 0.705 and 0.804, respectively (P<0.05), with the highest sensitivity (96.3%) for CCL20 and the highest specificity (95.43%) for CA724. The AUC was 0.915 when the three were combined for the diagnosis, with sensitivity and specificity of 91.36% and 87.67%, respectively. CONCLUSION The elevated levels of serum CCL20, CEA and CA724 were correlated with the occurrence of PLGC in CAG patients with Hp infection. The levels of these three markers were of certain values in assisting the diagnosis of PLGC associated with Hp infection, and the diagnostic efficiency could be improved when the three markers were combined detection.