（1. Key Laboratory of Polar Materials and Devices (MOE)， East China Normal University，
Shanghai 200241, China）
（2. Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, China）
Revealing the structure and chemical composition of materials at atomic scale is the basis and prerequisite for understanding the structure-property relationship of materials and tailoring their physical properties. Atomic scale chemical imaging based on energy dispersive X-ray spectroscopy (EDS) in Cs-corrected scanning transmission electron microscope has been the most powerful tool for studying the microstructure of solid crystal materials. In this paper, we first introduce the basic principle and frontier progress of atomic resolution EDS. Then, we take the application scenarios of atomic resolution EDS in revealing the atomic scale composition gradient in LaAlO3-SrTiO3 ferroelectric solid solution thin films, three-dimensional Ruddlesden-Popper fault networks in SmNiO3 thin films，the atomic migration in the phase change storage material Ge2Sb2Te5，the ordered segregation of solutes at oxide grain boundaries and the unique nanodomain structure in Cu-Zn-Sn-S thermoelectric ceramics as examples to demonstrate the analysis methods. Finally, the future development of the atomic resolution EDS is prospected.