Hydrogen　sulfide　(H2S)　is　a　highly　toxic　gas,　which　poses　a　serious　threat　to　human　health　and　safety.　It　is　necessary　to　develop　some　simple　and　highly　selective　and　sensitive　approach　for　the　detection　of　hydrogen　sulfide.　In　this　study,　a　highly　selective　and　sensitive　fluorescence　sensor　for　H2S　detection　has　been　developed　on　the　basis　of　Cu(II)-dependent　DNAzyme.　The　catalytic　DNA　strand　(Cu-enzyme)　was　labeled　with　a　quencher　(black　hole　quencher,　BHQ1)　at　the　5＇-termini　and　its　corresponding　DNA　substrate　strand　(Cu-substrate)　was　labeled　with　a　6-carboxyfluorescein　(FAM　fluorophore)　at　the　3＇-end　and　an　additional　quencher　was　attached　on　the　5＇-end.　Cu-enzyme　and　Cu-substrate　could　hybridize　with　each　other　to　form　a　triplex　structure　firstly　and　the　FAM　emission　was　quenched　by　the　labeled　quenchers.　The　present　of　Cu(II)　could　catalyze　the　oxidative　cleavage　of　the　Cu-substrate　and　hence　caused　the　releasing　of　the　quencher　from　the　FAM　fluorophore　and　the　enhanced　fluorescence　of　the　system.　However,　in　the　presence　of　H2S,　Cu(II)　reacted　with　H2S　to　form　CuS　firstly,　hindering　the　cleavage　and　the　fluorescence　enhancement　The　decrease　of　fluorescence　intensity　had　a　linear　relationship　with　the　concentration　of　H2S　in　the　range　between　0.5　and　25　mu　M　with　a　detection　limit　of　0.2　mu　M　(S/N　=　3).　The　proposed　method　innovatively　used　fluorescent　labeling　technology　and　DNAzyme　sensing　to　detect　gaseous　hydrogen　sulfide,　and　it　has　been　successfully　applied　to　detect　the　contamination　of　hydrogen　sulfide　gas　in　the　refuse　collectors　with　a　simple　purification　procedure.