The　current　rapid　industrial　development　generates　a　high　need　for　alternative　sustainable　sources　of　energy.　Artificial　photosynthesis,　which　can　directly　convert　solar　energy　into　usable　or　storable　energy　resources,　provides　such　a　promising　alternative.　Semiconductor　nanowires　have　gained　growing　interest　in　artificial　photosynthesis　due　to　their　unique　geometrical　and　electronic　characteristics,　which　can　provide　large　aspect-ratios,　direct　pathways　for　charge　transport,　decoupling　the　direction　of　charge　carrier　collection,　and　low　reflectance　induced　by　light　scattering　and　trapping.　In　particular,　heterostructured　semiconductor　nanowire　arrays　(NWAs)　have　recently　been　of　great　interest　in　artificial　photosynthesis　because　of　their　unique　structural　and　physicochemical　properties.　Nanowire　structure　can　lower　the　electrochemical　over-potential　while　the　heterojunctions　can　enhance　light　absorption　and　charge　separation,　which　thus　increase　the　artificial　photosynthesis　efficiency　of　heterostructured　semiconductor　NWAs.　In　this　review,　we　will　highlight　recent　advances　in　the　application　of　heterostructured　semiconductor　NWAs　to　artificial　photosynthesis.　An　emphasis　will　be　placed　on　the　unique　characteristics　and　benefits　of　using　heterostructured　semiconductor　NWAs　with　different　heterojunctions　for　artificial　photosynthesis,　as　well　as　the　associated　challenges　and　directions　for　future　research　in　this　area.　©　2016　The　Royal　Society　of　Chemistry.