Abstract: Helicobacter pylori is considered to be closely associated with gastritis, peptic ulcer, gastric cancer and other gastrointestinal diseases, but the detail of the pathogenesis is still unclear. The past researches often focused on virulence factors such as CagA (Cytotoxin-associated gene A), VacA (vacuolating cytotoxin A), Urease and DupA (duodenal ulcer-promoting gene), but these are not enough to reveal the pathogenic mechanism. Recent studies have not only revealed some new progresses of these past virulence factors but also indicated that Hp flagllum, adhesion protein and hemolysin play important roles in the pathogenic mechanism.

Key words: Helicobacter pylori, Virulence factor, Pathogenesis