Silver-loaded　stainless　steel　(Ag-SS)　was　applied　in　domestic　hot　water　system　(DHWS)　to　control　the　biofilm　contamination.　The　antibacterial　properties　of　Ag-SS,　as　well　as　the　bacterial　communities,　potential　pathogens　and　antibiotic　resistance　genes　(ARGs)　of　pipe　wall　biofilm　were　investigated,　with　SS　as　control.　Ag-SS　main-tained　a　high　antibacterial　efficiency　on　heterotrophic　bacteria　(70.60　?　13.22　%)　and　Escherichia　coli　(73.56　?　10.62　%)　by　contact　bacteriostasis.　Dominant　phyla　exhibited　a　lower　relative　abundance　in　Ag-SS　than　SS.　The　bacteria　were　further　classified　into　abundant　(?　1　%),　moderately　abundant　(0.1-1　%)　and　rare　(?　0.1　%)　taxa　to　investigate　their　responses　to　silver.　There　were　15.33　%　of　shared　operational　taxonomic　units　(OTUs)　belonged　to　abundant　taxa,　while　most　unique　OTUs　(＞　80　%)　of　each　sample　were　identified　as　rare　taxa.　As　the　primary　abundant　genera,　Mesorhizobium　and　Bradyrhizobium　exhibited　resistant　and　sensitive　to　silver,　respectively.　Most　dominant　moderately　abundant　and　rare　genera　were　resistant　to　silver.　Moreover,　among　19　detected　potential　pathogens,　Legionella,　Parachlamydia　and　Aeromonas　were　sensitive　to　silver,　while　Pseudo-monas　and　Acinetobacter　were　resistant　to　silver.　Furthermore,　a　total　of　48　ARGs　were　detected　and　they　exhibited　similar　distributions　in　both　samples.　The　total　abundance　of　ARGs　in　Ag-SS　increased　by　0.08　fold　compared　with　that　in　SS,　with　efflux　pumps　as　the　main　resistance　mechanisms.　This　study　highlights　the　different　responses　of　abundant,　moderately　abundant　and　rare　taxa　to　silver,　and　the　occurrences　of　ARGs,　confirming　that　Ag-SS　was　an　effective　disinfection　strategy　for　biosafety　protection　of　DHWS.