The development course of electron microscopy(EM) and its new functions in recent years are introduced in this article.In bio nanomaterials research,EM could be employed to carry out morphology characterization and in situ chemical analysis,but higher standards of experimental methods are necessary because of the diversity of biomaterials,the complexity of newly created nanostructures and their functionalities tightly connected with living cells/organs.Therefore,the strategies to develop advanced EM hardware and software required by these specialties of bio nanomaterials are systematically explained.Besides,the development directions for EM in field of bio nanomaterials research such as large size mosaic image with high resolution,three dimensional modeling of tiny and complicate structures,real time and in situ characterization and analysis during experiments are prospected.