Abstract: In recent years, significant advancements in molecular biology have paved the way for novel targeted therapeutic strategies for gastric cancer treatment. Claudin18, which is an important structural protein involved in tight junctions between cells, and its subtype Claudin18.2 (CLDN18.2), which is specifically expressed in differentiated gastric epithelial cells, have emerged as novel therapeutic targets for patients with gastric cancer. This article aims to systematically review the latest developments in CLDN18.2 research in the fields of basic and clinical gastric cancer studies to provide a reference for clinical practice.