The current study is designed to demonstrate the non-inferiority of CJ-12420-based triple therapy (CJ-12420, amoxicillin and clarithromycin) versus lansoprazole-based triple therapy (lansoprazole, amoxicillin and clarithromycin) in H. pylori eradication rate and to evaluate the safety of CJ-12420 following oral administration of either triple therapy twice daily for 7 days in H. pylori positive patients.