Abstract: Electrochromic materials are a kind of materials whose optical characteristics can be regulated with voltage reversibly. It is widely used in smart windows, displays, electrochromic sunroof, smart thermal management, military camouflage, and other fields. In recent years, electrochromic materials based on metal oxide nanocrystals have attracted extensive attention of researchers due to their excellent performance and cost advantages. In this paper, we first introduce the principle of electrochemically controlled localized surface plasmon resonance (LSPR) of nanocrystals. Then, we review the latest research progress of metal oxide nanocrystals and their compo-sites in traditional electrochromic and novel electrochromic fields based on electrochemically regulated LSPR. Finally, we put forward the existing problems and solutions of electrochromic materials based on metal oxide nanocrystals and their development prospects are prospected.