Abstract:Streptococcus gordonii is a nonpathogenic gram-positive commensal bacterium and component of the normal microbial flora of the human oral cavity. It is suitable to be as a mucosa vaccine vector due to its special bionomics. knowing the bionomics of Streptococcus gordonii , the general expressing system , and the application of it in mucosa vaccine, will provid important reference for the further development of its mucosa vaccine.