Abstract: Starting from electrical sizes of objects and devices, commonly adopted theories and numerical methods together with recent advances in research area of computational electromagnetics(CEM) are summarized. Then, based on analysis of the existing problems in this area, the importance, peculiarities, and corresponding challenges of nanoscale CEM are expounded. Finally, personal suggestions for research directions of the nanoscale CEM are presented. Moreover, the research works done by Chinese researchers are reviewed, and outlook of the CEM area is discussed.