Anthropogenic　perturbations　make　negative　effects　on　wetland　ecosystems,　such　as　increasing　levels　of　eutrophication.　Under　variable　environmental　conditions,　studying　the　processes　and　mechanisms　underlying　their　spatial　distribution　is　critical　to　biogeochemical　significance　of　microorganisms.　In　order　to　understand　the　changes　in　sediment　bacterial　community　and　their　assembly　with　long-term　eutrophication　of　the　Baiyangdian　Lake　of　China,　we　explored　the　microbial　communities　for　24　surface　sediment　samples　using　high　throughput　sequencing　of　V3-V4　region　of　16S　rRNA　gene,　meanwhile　we　employed　Neutral　community　model　(NCM)　to　characterize　the　community　assembly　processes.　Then,　the　β-nearest　taxon　index　(βNTI)　based　on　a　null　model　was　used　to　provide　a　quantitative　description　of　the　assembly　processes　of　the　bacterial　community.　Dispersal　limitation,　quantified　by　βNTI,　accounted　for　∼64.6%　of　all　assembly　processes.　As　the　increasing　levels　of　eutrophication,　deterministic　processes　of　bacterial　community　assembly　may　be　enhanced.　Moreover,　the　significant　correlation　between　the　βNTI　and　change　in　water　NO3−　or　sediment　pH　might　lead　to　deterministic　processes.　There　was　some　selection　pressure　acting　within　the　Baiyangdian　lake　sediments.　The　neutral　community　model　properly　explained　bacterial　community　assembly.　The　NO3−,　NH4+,　pH　and　EC　were　main　influencing　factors　on　the　composition　of　the　bacterial　community.　The　overlying　water　NO3−　surface　water　NO3−　and　sediment　pH　were　the　three　most　crucial　environmental　factors　to　drive　bacterial　assembly.　The　findings　revealed　that　Group　4　with　relatively　stronger　deterministic　processes　as　a　more　eutrophic　area　should　be　monitored　as　an　indicator　for　eutrophication　governance.　©　2022