Copper　oxide　nanoparticles　(CuO　NPs)　and　ciprofloxacin　(CIP)　have　ecological　risk　to　humans　and　ecosystems.　Polyvinylchloride　microplastics　(PVC　MPs),　as　a　representative　of　microplastics,　may　often　coexist　with　CuO　NPs　and　CIP　in　wastewater　treatment　systems　due　to　their　widespread　application.　However,　the　co-impact　of　PVC　MPs　in　wastewater　systems　contained　with　CuO　NPs　and　CIP　on　nitrogen　removal　and　ecological　risk　is　not　clear.　In　this　work,　PVC　MPs　co-impacts　on　the　toxicity　of　CuO　NPs　and　CIP　to　aerobic　granular　sludge　(AGS)　systems　and　potential　mechanisms　were　investigated.　10　mg/L　PVC　MPs　co-addition　did　not　significantly　affect　the　nitrogen　removal,　but　it　definitely　changed　the　microbial　community　structure　and　enhanced　the　propagation　and　horizontal　transfer　of　antibiotics　resistance　genes　(ARGs).　100　mg/L　PVC　MPs　co-addition　resulted　in　a　raise　of　CuO　NP　toxicity　to　the　AGS　system,　but　reduced　the　co-toxicity　of　CuO　NPs　and　CIP　and　ARGs　expression.　The　co-impacts　with　different　PVC　MPs　concentration　influenced　Cu2+　concentrations,　cell　membrane　integrity,　extracellular　polymeric　substances　(EPS)　contents　and　microbial　communities　in　AGS　systems,　and　lead　to　a　change　of　nitrogen　removal.　©　2023　Elsevier　Inc.