 Abstract single-atom catalysts, SACs, have been widely studied due to their high atom utilization efficiency and unique electronic properties. These catalysts can be modified by changing the local coordination structures, which can significantly influence their performance in various energy conversion processes. In particular, dynamic changes in the local coordination structures of SACs during electrochemical reactions have not yet been fully understood. This review focuses on the dynamic evolutions of local coordination structures of SACs in various electrochemical reactions, using advanced operando slash in-situ techniques. It demonstrates how these dynamic changes correlate with the catalytic activity of SACs and discusses the challenges and perspectives of further research. This article was authored by Huying Tan, Jelly Wang, Xingqi Lin, and others.