Electrochemical nitrogen reduction reaction (e-NRR) under ambient conditions is an emerging strategy to tackle the hydrogen-and energy-intensive operations for traditional Haber-Bosch process in industrial ammonia (NH3) synthesis.However,the e-NRR performance is currently impeded by the inherent inert-ness of N2 molecules,the extremely slow kinetics and the overwhelming competition from the hydrogen evolution reaction (HER),all of which cause unsatisfied yield and ammonia selectivity (Faradaic effi-ciency,FE).Defect and interface engineering are capable of achieving novel physical and chemical prop-erties as well as superior synergistic effects for various electrocatalysts.In this review,we first provide a general introduction to the NRR mechanism.We then focus on the recent progress in defect and interface engineering and summarize how defect and interface can be rationally designed and functioned in NRR catalysts.Particularly,the origin of superior NRR catalytic activity by applying these approaches was dis-cussed from both theoretical and experimental perspectives.Finally,the remaining challenges and future perspectives in this emerging area are highlighted.It is expected that this review will shed some light on designing NRR electrocatalysts with excellent activity,selectivity and stability.