In　despite　of　significant　progresses　have　been　accomplished　in　the　programming　and　development　of　updated　and　efficient　nana-catalysts　for　H2　production　from　a　wide　variety　of　chemical　hydrogen　storage　materials.　However,　it　is　a　practical　matter　of　the　utmost　importance　to　develop　the　＂on-off＂　control　for　on　demand　H2　release　in　the　cause　of　effectively　and　safely　producing,　carrying　and　depositing　H2　gas.　Herein,　we　have　first　designed　and　synthesized　a　sequence　of　carbon　nanosphere　(CNS)-stabilized　bimetallic　PtNi　nanoparticles　(PtNi/CNS),　by　stabilization　of　nearly　monodispersed　PtNi　bimetallic　nanoparticles　onto　the　surface　of　carbon　nanosphere,　for　the　highly　selective　and　efficient　on-demand　H2　release　upon　the　dehydrogenation　of　hydrous　hydrazine.　Then,　the　optional　nanocatalyst　Pt1Ni1/CNS　exhibits　the　highest　catalytic　performance　in　hydrogen　production　from　dehydrogenation　of　hydrous　hydrazine,　with　100　%　H2　selectivity　and　the　turnover　frequency　(TOF)　of　3928　mol　(H2)center　dot　molcat　-　1　center　dot　h-1　at　50　degrees　C.　The　detailed　physical　characterizations　have　confirmed　that　the　superior　catalytic　performance　of　Pt1Ni1/CNS　in　the　H2　release　upon　hydrous　hydrazine　dehydrogenation　is　attributed　to　the　electronic　interaction　and　synergistic　effect　between　Ni　and　Pt.　More　importantly,　the　highly　selective　＂on-off＂　control　for　demand-based　H2　release　upon　the　dehydrogenation　of　hydrous　hydrazine　is　successfully　realized　by　pH　regulation.