Abstract: CLDN18.2 is a tight junction protein expressed in normal gastric mucosa.It participates in the formation of tight junctions and affects the permeability of paracellular ions.The rate of CLDN18.2 positivity in gastric cancer is approximately 40%.The expression specificity of CLDN18.2 makes it a potential target for treating gastric cancer.The combination of IMAB362, an antibody targeting CLDN18.2, and chemotherapy could considerably prolong the survival of CLDN18.2-positive gastric cancer patients.IMAB362 has the potential to be the first-line treatment for gastric cancer.However, because of obstacles in developing detection antibodies, studies on CLDN18.2 are rare.In addition, since the clinical trial on CLDN 18.2 is in its initial stage, the results of the current study remain unclear. Consequently, there is still no holistic view on CLDN18.2-positive gastric cancer.Therefore, we mainly reviewed all previous studies and progress related to CLDN18.2 to integrate CLDN18.2-related progress while aiming to provide a reference for clinical and translational research on CLDN18.2-positive gastric cancer and possible ideas for its future development direction.