Inclusion criteria:

1. Patients with gastric ulcer (A1-and A2-stage)

2. Patients with gastric ulcer who meet all of the following items. Gender and treatment class (in-patient or out-patient) are not asked.

   • Patients with endoscopically diagnosed A1- or A2-stage ulcer (by Sakita/Miwa classification).
   • Patients who are not younger than 20 years of age at the time of obtaining informed consent.

   • Patients who meet any of the following conditions:

     • H. pylori-negative
     • H. pylori-positive and not requiring eradication therapy
     • H. pylori-positive and unsuccessful eradication
3. Patients who are given a full explanation about the study objective and design, and able to give prior consent for study participation.

Exclusion criteria:

1. Patients with a complication of duodenal ulcer (excluding cicatrix).
2. Patients with reflux esophagitis
3. Patients with acute gastric mucosal lesions (AGML).
4. Patients with NSAID-induced ulcer.
5. Patients with linear ulcer.
6. Patients with ulcer injured by endoscopy.
7. Patients who underwent gastrectomy or vagal nerve resection.
8. Patients who are not applied to pharmacotherapy, i.e., perforation, pyloric stenosis, major bleeding (exposed blood vessels in the base of ulcer), etc.
9. Patients receiving proton pump inhibitor (PPI) and/or teprenone preparation(s) within 1 week prior to the study administration.
10. Patients with serious cardiovascular diseases (e.g., angina pectoris, heart failure, acute myocardial ischemia, severe tachyarrhythmia), serious hematological disorders (e.g., aplastic anemia), serious renal disorders (e.g., acute, chronic renal failure), serious hepatic disorders (e.g., cirrhosis, severe hepatitis), serious pancreatic disorders (e.g., severe pancreatitis), serious psychoneuroses (e.g., schizophrenia, alcoholic dependency, drug dependency, severe depression), or cancer.
11. Patients with a current or a history of drug allergy to teprenone preparation(s).
12. Patients with a current or a history of drug allergy to PPI.
13. Patients requiring antacid(s) containing digoxin or aluminum hydroxide/magnesium hydroxide that are suspected to exert drug interaction with rabeprazole sodium.