Abstract:The pathogenic mechanism of Streptococcus suis serotype 2 is still unsolved. Pathogenicity island not only gives pathogen special ability of pathogenic but also plays an important role in bacterial evolution process. Thorough analysis of the functional genes in 89K pathogenicity island contributes to a more comprehensive grasp of the characteristics of Streptococcus suis serotype 2. This paper summarized the structure and evolution process of 89K pathogenicity island and the research progress of domestic and foreign, including in two-component signal transduction system, type IV secretion system, ATP-binding cassette transporter protein, toxin-antitoxin system and other important genes, trying in gene level to find a breakthrough in pathogenesis of Streptococcus suis serotype 2.