In addition to an upper gastrointestinal radiograph, an upper gastrointestinal endoscopic examination has also been recommended as a strategic screening method for gastric cancer and is expected to play a central role in the gastric cancer screening in the near future. On the other hand, H. pylori infection and the associated atrophy and inflammation of gastric mucosa have been demonstrated to be closely related to the development of gastric cancer. Therefore it is crucial to determine the H. pylori infection for the gastric cancer screening. Blood tests enable stratification of gastric cancer risk and their use can lead to efficient gastric cancer screening. ABC classification using a combination of the detection of serum anti-H. pylori antibody and measurement of the level of serum pepsinogens is a method to classify the background gastric mucosa by a simple blood test, which enables risk stratification of not only gastric cancer but also the other upper gastrointestinal diseases. Stratification the gastric cancer risk by ABC classification, reduction of the risk by H. pylori eradication, and surveillance after eradication are all important for strategy for the gastric cancer.