Water　scarcity　is　a　critical　issue　in　desert　and　arid　regions,　and　atmospheric　water　harvesting　is　a　potential　solution.　The　challenge　is　lacking　ideal　adsorbents　that　can　efficiently　capture　water　from　low-humidity　air　and　be　regenerated　readily.　Herein,　we　report　a　hydrolytically　stable　metalorganic　framework　(MOF),　[Cu-2(AD)(2)(SA)]　(Cu-AD-SA),　with　excellent　performance　in　water　harvesting.　More　importantly,　this　material　can　be　facilely　prepared　from　two　easily　accessible　ligands　adenine　(HAD)　and　succinic　acid　(H(2)SA).　Cu-AD-SA　has　a　three-dimensional　(3D)　framework　structure　with　the　crs　topology　and　intersecting　channels　of　similar　to　5　angstrom　in　diameter.　The　channel　surface　is　decorated　by　uncoordinated　aromatic　N　atoms,　amine　groups,　and　alkyl　moieties.　Interestingly,　Cu-AD-SA　shows　a　high　water　adsorption　capacity　of　0.16　g　g(-1)　at　low　pressure　of　0.2　P/P-0　and　25　degrees　C.　Furthermore,　dynamic　water　adsorption-desorption　cycling　experiments　demonstrated　a　stable　working　capacity　of　0.13　g　g(-1)　for　uptaking　water　from　a　low-humidity　air　(water　partial　pressure:　0.85　kPa,　20%　RH　at　30　degrees　C,　5.3%　RH　at　55　degrees　C)　at　30　degrees　C　and　desorption　at　55　degrees　C.　The　water　adsorption　mechanism　was　also　studied　by　analyzing　its　single-crystal　structure　after　water　loading.　The　results　indicated　the　existence　of　strong　H-bonding　interactions　between　water　molecules　and　uncoordinated　N　atoms　and　amine　groups　on　the　framework,　which　should　play　an　important　role　in　the　high　adsorption　at　low　pressure.　All　the　above　features　suggest　great　potential　of　Cu-AD-SA　for　water　harvesting　in　arid　regions.