This paper briefly reviewed the principle and characteristics of XPS in surface analysis, and described its specific application in material research. The position, shape and intensity of XPS peaks can be used for determining the chemical valence and content of elements. Ultrathin sample can be analyzed by the angle-resolved XPS method. Imaging XPS could show the distribution of element on the surface of samples and its chemical valence. Through depth profiling using argon-ion etching, the variation of sample chemical state with depth can be revealed.