Volatile　sulfur　compounds　(VSCs)　released　by　each　treatment　unit　of　urban　sewage　treatment　plants　were　long-term　monitored,　and　the　sensory　effects　and　health　risks　brought　by　VSCs　were　evaluated.　The　results　showed　that,　from　the　point　of　view　of　concentration,　VSCs　were　dominated　by　H2S　(the　H2S　concentration　during　the　monitoring　period　was　N.D.~580μg/m3),　and　the　concentration　of　methyl　mercaptan　(MT)　accounts　for　the　least　(the　concentration　of　MT　during　the　monitoring　period　was　N.D.~4.7μg/m3),　and　the　concentration　distribution　of　VSCs　had　obvious　seasonality,　that　was,　summer＞autumn＞winter.　In　terms　of　sensory,　H2S　was　the　gas　the　contributes　the　most　to　the　odor　of　all　VSCs　(the　contribution　rate　was　79%~93%),　except　for　secondary　sedimentation.　Outside　the　tank,　it　was　a　key　malodorous　gas　in　other　processing　units;　although　the　MT　concentration　level　was　low,　its　contribution　to　odor　cannot　be　ignored;　the　odor　activity　value　(SOAV)　of　the　mixed　gas　of　the　grid　and　the　grit　tank　were　2591.9,　5494.8,　the　pretreatment　unit　contributed　the　most　to　the　smell　of　the　plant.　In　terms　of　health　risks,　there　was　a　non-carcinogenic　risk　of　H2S　in　the　grille　and　grit　tank　in　spring　and　summer.　©　2021,　Editorial　Board　of　China　Environmental　Science.　All　right　reserved.