Renewable-energy-powered　electrochemical　CO2　reduction　(ECR)　is　a　promising　way　of　transforming　CO2　to　value-added　products　and　achieving　sustainable　carbon　recycling.　By　virtue　of　the　extremely　high　exposure　rate　of　active　sites　and　excellent　catalytic　performance,　atomic　site　catalysts　(ASCs),　including　single-atomic　site　catalysts　and　diatomic　site　catalysts,　have　attracted　considerable　attention.　In　this　feature　article,　we　focus　on　the　rational　design　strategies　of　ASCs　developed　in　recent　years　for　the　ECR　reaction.　The　influence　of　these　strategies　on　the　activity　and　selectivity　of　ASCs　for　ECR　is　further　discussed　in　terms　of　electronic　regulation,　synergistic　activation,　microenvironmental　regulation　and　tandem　catalytic　system　construction.　Finally,　the　challenges　and　future　directions　are　indicated.　We　hope　that　this　feature　article　will　be　helpful　in　the　development　of　novel　ASCs　for　ECR.　©　2023　The　Royal　Society　of　Chemistry.