The present invention relates to a composition, kit and information provision method, for discovering pepsinogen II as a biomarker for predicting or diagnosing early-stage diffuse gastric cancer, and enabling predicting or diagnosing early-stage diffuse gastric cancer according to the level of pepsinogen II measured in a subject. The composition, kit and information provision method, according to one aspect of the present invention, may predict or diagnose early-stage diffuse gastric cancer with high sensitivity and specificity when the level of serum pepsinogen II is equal to or greater than 20 µg/L, and further, may classify the risk of early-stage diffuse gastric cancer in a subject on the basis of whether the level of serum pepsinogen II is equal to or greater than 20 µg/L, and whether the status of Helicobacter pylori (HP) is positive. Thus, the composition, comprising a preparation capable of measuring the level of serum pepsinogen II, or, along with said preparation, a preparation capable of detecting the status of HP, the kit and the information provision method using same have an excellent effect of being capable of being usefully employed as non-invasive means which may be carried out prior to an endoscopy.