Granule-based　partial　denitrification　(PD)　is　a　technology　that　can　supply　stable　nitrite　for　applying　anaerobic　ammonia　oxidation　in　wastewater　treatment,　and　triclosan　(TCS)　is　a　frequently　detected　antibacterial　agent　in　wastewater　treatment　plants,　therefore　it　is　possible　that　TCS　could　enter　into　wastewater　that　is　treated　using　PD　technology.　However,　the　active　microorganisms　responsible　for　PD　and　TCS　removing　in　granule-based　PD　system　have　not　been　clearly　identified　and　it　is　currently　not　clear　how　TCS　affects　the　PD　process.　In　this　study,　the　impacts　of　TCS　on　PD　performance,　PD　microbial　community,　antibiotic　resistance　genes　(ARGs),　active　PD　bacteria　and　TCS-degrading　bacteria　in　a　granule-based　PD　system　were　investigated.　3　mg/L　TCS　had　adverse　influence　on　PD　process,　but　PD　system　could　recover　gradually　after　inhibiting　of　10　days.　After　a　period　of　domestication,　PD　granular　sludge　could　achieve　10.66%　of　TCS　degradation　efficiency　and　43.62%　of　TCS　adsorption　efficiency.　Microbes　might　increase　their　resistance　to　TCS　by　increasing　the　secretion　of　extracellular　polymeric　substances,　and　the　secretion　of　protein　might　play　a　more　pivotal　role　than　the　secretion　of　polysaccharides　in　resisting　TCS.　The　short-term　shock　of　TCS　might　cause　the　propagation　of　acrA-03,　while　the　longterm　operation　of　TCS　could　propagate　fabK　and　intI1.　DNA　stable　isotope　probing　assay　indicated　that　Thauera　was　active　PD　bacteria　and　TCS-degrading　bacteria　in　the　granule-based　PD　system,　and　it　could　contribute　to　nitrite　accumulation　and　TCS　degradation,　simultaneously.