A　PCL-degrading　strain　was　isolated　and　identified　as　Pseudomonas　sp.　JQ-H3　through　morphology　observation　and　phylogenetic　analysis.　The　strain　showed　the　heterotrophic　nitrification-aerobic　denitrification　(HN-AD)　ability　using　PCL　as　a　sole　carbon　source.　About　93.11%　of　initial　ammonium　(102.41mg/L)　was　degraded　within　36h　with　the　maximum　ammonium　removal　rate　of　5.77mg/(L•h),　while　approximately　93.93%　of　initial　nitrate　(99.01mg/L)　was　removed　within　48h　with　the　maximum　ammonium　removal　rate　of　4.12mg/(L•h).　94.03%　of　PCL　film　with　initial　weight　of　100mg　was　decomposed　after　60days,　and　the　extracellular　lipases　activity　reached　the　maximum　value　of　9.18mU/mL　at　30th　days.　In　addition,　the　expression　levels　of　amoA　and　nirS　genes　were　promoted　in　the　weak　alkaline　environment.　The　successful　expression　of　napA,　cnorB　and　nosZ　genes　further　proved　the　HN-AD　ability　of　the　strain　JQ-H3.　©　2019,　Editorial　Board　of　China　Environmental　Science.　All　right　reserved.