Knowledge　gaps　still　surround　the　question　of　what　biofilms　form　on　contaminated　microplastics　(MPs)　in　the　antibiotics　and　(or)　heavy　metals　polluted　sewage.　In　this　work,　the　clean　polyethylene　microplastics　(PE　MPs)　and　triclocarban　(TCC)-contaminated　PE　MPs　were　cultured　in　the　sewage　containing　only　ampicillin　(AMP),　only　copper　(Cu)　and　both　AMP　and　Cu　for　28　days.　The　results　showed　that　the　TCC　on　PE　MPs　(with　concentration　of　2.48　mg/g　PE　MPs)　did　not　impede　the　adhesion　of　the　bacteria　and　the　formation　of　biofilm.　Moreover,　many　potential　pathogenic　bacteria　(Aquabacterium　and　Pseudoxanthomonas)　and　potential　resistant　bacteria　(Stenotrophomonas)　were　more　likely　to　attach　on　TCC-contaminated　PE　MPs　compared　with　clean　PE　MPs.　In　addition,　biofilms　of　TCCcontaminated　PE　MPs　had　highest　potential　pathogenic　functions.　TCC-contaminated　PE　MPs　also　caused　the　increases　of　various　resistance　genes　in　both　biofilm　and　sewage.　The　co-occurrence　of　TCC,　AMP　and　Cu　might　exert　a　stronger　selective　pressure　on　bacterial　communities　and　promote　the　co-selection　of　resistance　genes.　In　addition,　TCCcontaminated　PE　MPs　resulted　in　higher　abundance　of　five　mobile　genetic　elements　(MGEs)　(intI1,　intI3,　tnpA-04,　IS613　and　trb-C)　in　sewage,　which　might　further　promote　the　transmission　of　resistance　genes.