Abstract: OBJECTIVE To review the main applications of scanning electron microscopy(SEM) and energy dispersive spectroscopy(EDS) in the characterization of dry powder inhaler formulations(DPI).METHODS Through literature research and induction, using SEM-EDS method to characterize the dry powder inhaler formulation, using SEM based automatic particle shape and size analysis software to perform statistical analysis of carrier particles, to summarize the key application scenarios of SEM-EDS in the scientific research or development of DPI formulations.RESULTS DPI was a preparation type highly dependent on particle engineering. Its performance and therapeutic efficacy largely depended on the micro characteristics of active pharmaceutical ingredient(API) and carrier. The size and shape of carrier particles played a decisive role in efficient lung transport. The surface roughness of carrier particles directly affected the adhesion-desorption balance between API and carrier particles, and finally directly affected the atomization performance of the preparation. SEM could quickly evaluate the particle size, particle shape and surface roughness. In addition, the loading of API on carrier particles and the desorption capacity of API-carrier system could also be judged by SEM-EDS analysis.CONCLUSION SEM-EDS has extensive application significance in the research and development of DPI preparations, it provides an advanced characterization method for the research and development of this type of preparations.