致病岛是指细菌染色体上具有的一段典型结构特征的基因簇，主要编码与细菌的毒力及代谢等功能相关的产物。Ⅳ型分泌系统则是指在革兰氏阴性菌中由不同的蛋白分子构成的，主要将毒力因子通过细胞膜分泌到胞外，与宿主细胞发生相互作用而发挥其毒性的分泌系统。幽门螺杆菌致病岛及其编码的Ⅳ型分泌系统是幽门螺杆菌的关键性致病因子，有可能成为药物作用的新靶标，是近年相关研究的关注热点。本文仅就近年来之研究现状作一综述。

Pathogenicity island is a gene cluster that have special structure and located in bacterial chromosome,which function is code productions that associated with bacterial virulence and metabolism. Type Ⅳ secretion system（T4SS）is an important export pathway used by Gram-negative pathogenic bacteria to inject bacterial proteins into the cytosol of eukaryotic host cells.Cag and type Ⅳ secretion system coded by cag, a pathogenicity island(PAI) of Helicobacter pylori, were all the key factors to cause diseases. While which was a burning question in related fields recently, and would also be a new target for medical treatment. This review summarized the recent studies on it.