There is still high stomach cancer though its mortality rate Helicobacter pylori has tended to decrease for the past several years. Study of Helicobacter pylori become more active as the relation between the stomach cancer and Helicobacter pylori has been clarified. In the present study, we added considerations from the literature in terms of oxidation stress with Helicobacter pylori about the underlying mechanism of the stomach cancer. Moreover, we referred to the relation between adenocarcinoma at the oesophagogastric junction and the oxide of nitrogen as clarified by recent study. Additionally, the role of anti-oxidant biofactors such as vegetables and fruits were considered from the viewpoint of cancer prevention in light of recent findings.