Inclusion Criteria:  participants was confirmed chronic atrophic gastritis by endoscopy participants has not been previously received treatment for H.pylori infection.  Exclusion Criteria:  patients who were allergic to any study medications patients who had taken antibiotics,bismuth agent,PPI or H2 receptor antagonist (H2RA) 4 weeks before the study patients with previous gastrectomy patients with malignancy or severe comorbidity pregnant or lactating women Patients with poor treatment compliance or could not express themselves correctly patients who participated in other drug trial recently (within 3 months of enrollment).