A phase 2,double-blinded, double dummy, parallel, positive drug, randomised controlled multicenter trial to evaluate efficacy and safety of 4 weeks treatment of Anaprazole 20mg QD, 40mg QD compared with rabeprazole 10mg QD in patients with duodenal ulcers.

Inclusion Criteria:

1. Age ≥18 years, male and female
2. Has endoscopic diagnosis of active duodenal ulcer(s) (A1 or A2 stage) within 7 days prior to randomization
3. 1 or 2 ulcers, 3-15 mm in diameter.
4. Signed informed concent form

Exclusion Criteria:

1. Has malignancy ulcer or malignancy ulcer not excluded, compouned ulcer, stress ulcer, esophageal erosion and ulcer, reflux esophagitis, Zollinger-Ellison syndrome.
2. Has esophageal and gastric varices；
3. With severe compliaction, such as pyloric obstruction, bleeding (Forrest I, IIa and IIb) or perforation, and etc；
4. Has other gastrointestinal disease (e.g.gastric ulcer), or has history of inflammatory bowel disease (such as Crohn's disease or ulcerative colitis)；
5. Has undergone surgical resection or partly resection of esophageal, stomach or duodenum；
6. Has used Proton Pump Inhibitors(PPIs) within 5 days prior to randomization, or continuous more than 3 days of use of Proton Pump Inhibitors within 2 weeks prior to randomization；
7. Has been treated with triple or quandruple Helicobacter pylori eradication therapy included PPIs within 28 days prior to randomization；
8. Current use the drugs (such as systemic glucocorticoids, non steroid anti-inflammatory drugs, or anticoagulation drugs) which may induce ulcer or ulceric bleeding or continuous more than 3 days of use the drugs (such as systemic glucocorticoids, non steroid anti-inflammatory drugs, or anticoagulation drugs) within 28 days prior to randomization；
9. Laboratory tests performed in screning stage revealed Alanine aminotransferase (ALT) or aspartate aminotransferase (AST): > 1.5 upper limit of normal (ULN);
10. Laboratory tests performed in screning stage revealed thyroid stimulating hormone (TSH)；
11. Woman in pregnancy or lactation period；
12. Plan for pregancy or not willing to contracept with reliable contraception method during study period and within 90 days after the final time of investigational drug administratio；
13. Have alcohol abuse or drug abuse 1 years prior to screening；
14. Has hypersensitivity or allergy to investigatory drug, comparatory drug or related supplements；
15. Has participated or been participating other clinical trials(non-interventional study is excluded)；
16. Has an uncotroled disease, such as has a history of significant central nervous system (CNS), cardiovascular, pulmonary, hepatic, renal, or mental or psychological disorders with drug treatment that,in the opinion of the investigator, would not be suitable for participating this clinical trial.
17. In the opinion of the investigator, the patients with other situation would not be suitable for participating this clinical trial.