Inspired　by　cytoskeletal　structures　that　respond　sensitively　to　environmental　changes　and　chemical　inputs,　we　report　a　strategy　to　trigger　and　finely　control　the　assembly　of　stimulus-responsive　DNA　nanostructures　with　light　under　isothermal　conditions.　The　strategy　is　achieved　via　integrating　an　upstream　light-controlled,　toehold-mediated　DNA　strand　displacement　circuit　with　a　downstream　DNA　tile　self-assembly　process.　By　rationally　designing　an　upstream　DNA　strand　module,　we　further　transform　the　upstream　DNA　strand　displacement　circuit　to　an　＇AND　gate＇　circuit　to　control　the　assembly　of　DNA　nanostructures.　This　example　represents　the　demonstration　of　the　spatial　and　temporal　assembly　of　DNA　nanostructures　using　a　noninvasive　chemical　input.　Such　a　light-controlled　DNA　logic　circuit　not　only　adds　a　new　element　to　the　tool　box　of　DNA　nanotechnology　but　also　inspires　us　to　assemble　complex　and　responsive　nanostructures.　Copyright　©　2020　American　Chemical　Society.