ZnS　is　among　the　superior　photocatalysts　for　H2　evolution,　whereas　the　wide　bandgap　restricts　its　performance　to　only　UV　region.　Herein,　defect　engineering　and　phase　junction　architecture　from　a　controllable　phase　transformation　enable　ZnS　to　achieve　the　conflicting　visible-light-driven　activities　for　H2　evolution.　On　the　basis　of　first-principle　density　functional　theory　calculations,　electron　spin　resonance　and　photoluminescence　results,　etc.,　it　is　initially　proposed　that　the　regulated　sulfur　vacancies　in　wurtzite　phase　of　ZnS　play　the　key　role　of　photosensitization　units　for　charge　generation　in　visible　light　and　active　sites　for　effective　electron　utilization.　The　symbiotic　sphalerite-wurtzite　phase　junctions　that　dominate　the　charge-transfer　kinetics　for　photoexciton　separation　are　the　indispensable　configuration　in　the　present　systems.　Neither　ZnS　samples　without　phase　junction　nor　those　without　enough　sulfur　vacancies　conduct　visible-light　photocatalytic　H2　evolution,　while　the　one　with　optimized　phase　junctions　and　maximum　sulfur　vacancies　shows　considerable　photocatalytic　activity.　This　work　will　not　only　contribute　to　the　realization　of　visible　light　photocatalysis　for　wide-bandgap　semiconductors　but　also　broaden　the　vision　on　the　design　of　highly　efficient　transition　metal　sulfide　photocatalysts.　(Figure　Presented).　©　2015　American　Chemical　Society.