 Clarithromycin-based triple therapy containing a proton-pump inhibitor PPI twice daily, amoxicillin 1g twice daily, and clarithromycin 500 mg twice daily for 7 days is one of the standard firs-line therapy for Helicobacter pylori eradication. However, because of unsatisfactory eradication rate 80-85, the Maastricht III guideline recommended extending the treatment duration to increase the eradication rate. Recently, levofloxacin 500 mg qd-based triple therapy has been shown to achieve an eradication rate of 90 for both the first- and second-line treatment for H. pylori eradication. Several studies have demonstrated that high dose 750mg and short-course 5 days levofloxacin is as effective and well tolerated as traditional dose 500mg and course 10 days for treatment of mild-to-severe community acquired pneumonia. The high dose and short-course therapy has the potential to increase patient compliance and reduce bacterial resistance to fluoroquinolones. However, whether increasing the dosage of levofloxacin from 500mg to 750 mg qd can augment the efficacy of triple therapy in eradication of H. pylori and shorten the duration of therapy remains unknown. Although levofloxacin-based regimen was presumed to be more effective, previous reports pointed the concern that resistance to fluoroquinolone and other antibiotics which susceptible to the pumping efflux of bacteriae would increase among the gut flora. 