The purpose of this article is to research the appearance of band structures and surface modes in semi-infinite periodically layered media. By the analysis, the spread of passing band and forbidden band for the foundation of design is investigated. This article use transfer matrix method to calculate dispersion relation and surface modes in semi-infinite periodically layered media. Finally analyzing characteristics of periodical structures in two-layer and four-layer to research the influence of width, structure, cap layer on band structures and surface modes is presented.