Periodontitis is known to be a risk factor for abdominal aortic aneurysm(AAA).However,the influence of periodontitis on AAA development is to be elucidated.This article is to review the relationship between periodontitis and AAA.We focused on the roles of specific periodontopathic bacteria in AAA,matrix metalloproteinases and toll-like receptors in the pathophysiology in the section of experimental analysis.Furthermore,we showed clinical data of periodontitis in patients with AAA.We concluded that periodontal pathogens play a critical role in the AAA development.