【Abstract】 Objective To investigate the relationship between methylation of tumor suppressor gene and gastric cancer. Methods The literatures in recent years about the concept of methylation, its biological significance and the relationship between DNA methylation/demethylation and gastric cancer were reviewed. The effects of methylation of different tumor suppressor genes on gastric cancer were also analyzed. Results The effect of aberrant methylation on the development and the progression of gastric cancer was still unclear but it was supposed that the inactivation of genes related with cell cycle regulation, mitotic checkpoint, apoptosis, DNA mismatch repair, metastasis suppression and so on might be attributable to the aberrant methylation in gastric cancer. Conclusion Aberrant methylation of tumor suppressor genes plays an important role in the development and progression of gastric cancer. The status of methylation of tumor suppressor genes may be used as a useful molecule marker for diagnosis, assessing metastasis and evaluating prognosis, and demethylation could possibly be a new therapy for gastric cancer.