Abstract: As one of the human runt-related transcription factors, the RUNX3 gene is found to be an anti-oncogene. It plays an important role in the TGF- βsignaling pathway. The mechanism of RUNX3 inactivation involves loss of heterozygosity (LOH) and promoter hypermethylation, resulting in the development and metastasis of gastric cancer. The structure and function of RUNX3 and the relationship between the RUNX3 gene and gastric mucous hyperplasia as well as gastric cancer are reviewed in the article.