Abstract: Abnormal methylation of the tumor-related genesis frequently found in the development of gastric cancer. Cancer cells exhibit two opposing methylation abnormalities: genome-wide hypomethylation and certain tumor suppressor gene hypermethylation. Furthermore, it seems that the level of DNA methylation is closely associated with the prognosis of gastric cancer. Recently, a great deal of research has been conducted to reveal thecorelation of DNA methylation and gastric cancer.