This review briefly summarizes recent progress in defect electrocatalysts,and the synthesis strategies and characterization techniques for defects are systematically discussed.Although challenges in the characterization of defect structures in the electrocatalytic reaction process remain,the dynamic evolution of defect sites is predicted to be helpful for designing and preparing high-performance electrocatalysts for commercial applications.Furthermore,due to an insufficient understanding of the defect-structureproperty relationships,future possibilities for the reasonable design of defect electrocatalysts to obtain desirable performance are suggested.