Ground-level　ozone　(O3)　poses　a　threat　to　both　human　health　and　ecosystems;　the　development　of　O3　decom-position　catalysts　is　thus　of　fundamental　and　practical　significance.　In　the　past　decades,　metal　oxides　have　been　widely　investigated　for　O3　elimination　due　to　their　low　cost　and　high　catalytic　activity.　Recently,　it　has　been　demonstrated　that　metal-organic　frameworks　(MOFs)　could　also　show　high　performance　in　the　removal　of　O3　and　even　other　airborne　gaseous　pollutants　at　the　same　time.　Herein,　we　report　a　facile　synthetic　method　to　prepare　the　composite　of　the　well-known　MOF,　UiO-66-NH2,　and　birnessite-type　manganese　dioxide,　namely,　(5-MnO2,　where　the　nanosheets　of　(5-MnO2　are　vertically　aligned　and　densely　grown　on　the　crystal　surfaces　of　UiO-66-NH2.　The　(5-MnO2/UiO-66-NH2　composite　could　completely　remove　low-concentration　O3　(5　ppm)　in　both　dry　and　highly　humid　(RH　=　80%)　air　at　ambient　temperature　and　pressure　with　a　space　velocity　of　2000　L　h-1　g-1.　In　contrast,　a　single-phase　sample　of　(5-MnO2　or　the　typical　O3　decomposition　catalyst,　a-MnO2,　showed　a　much　lower　O3　removal　efficiency　under　the　same　experimental　conditions.　Due　to　the　ultrathin　morphology　(high　surface　area)　and　well-separated　distribution　(no　aggregation)　of　(5-MnO2　nanosheets　in　the　(5-MnO2/UiO-66-NH2　composite,　there　are　rich　Mn2+/Mn3+　atoms　and　oxygen　vacancies　on　its　surface,　contributing　to　its　high　performance　in　catalytic　O3　decomposition.　This　work　demonstrated　a　facile　method　to　prepare　MOF-based　composites　with　fascinating　nanostructures　and　high　catalytic　activity　in　O3　decomposition,　which　are　also　potentially　useful　in　other　catalytic　reactions.