Abstract: Q fever caused by ICoxiella burnetii/I is a zoonoses with worldwide distribution. At present, the global anti-terrorism organization has included the pathogen as a biological warfare agent. Although antibiotics is effective for acute patient, the treatment of chronic Q fever usually needs a long period with high relapse rate and case-fatality.Otherwise, Q fever is difficult to control once epidemic occurs and lead to consequent great harm to mankind because the pathogen could be spread by aerosol. To provide reference for the further study of pathogenesis, providing timely and effective diagnostic techniques and development of ICoxiella burnetii/I vaccine, this paper summaries the progress on the molecular biology research of ICoxiella burnetii/I.