Despite　the　growing　recognition　regarding　the　carbon　cycle　in　the　rhizosphere　of　upland　ecosystems,　little　is　known　regarding　the　rhizosphere　effect　on　soil　organic　carbon　(SOC)　mineralization　in　tidal　marsh　soils.　In　the　current　study,　in　situ　rhizobox　experiments　(including　rhizosphere　and　inner　and　outer　bulk　soil)　were　conducted　in　an　estuarine　tidal　marsh.　Our　results　showed　that　a　higher　abundance　of　total　bacteria,　Geobacter,　dsrA　and　mcrA　and　lower　α-diversity　were　observed　in　the　rhizosphere　relative　to　the　bulk　soil.　Rhizosphere　effects　shifted　the　partition　of　terminal　metabolic　pathways　from　sulfate　reduction　in　the　bulk　soil　to　the　co-dominance　of　microbial　Fe(III)　and　sulfate　reduction　in　the　rhizosphere.　Although　the　rhizosphere　effect　promoted　the　rates　of　three　terminal　metabolic　pathways,　it　showed　greater　preference　towards　microbial　Fe(III)　reduction　in　the　tidal　marsh　soils.　Plant　species　had　little　impact　on　the　partitioning　of　terminal　metabolic　pathways,　but　did　affect　the　potential　of　total　SOC　mineralization　together　with　the　abundance　and　diversity　of　total　bacteria.　Both　the　rhizosphere　effect　and　plant　species　influenced　the　bacterial　community　composition　in　the　tidal　marsh　soils;　however,　plant　species　had　a　less　pronounced　impact　on　the　bacterial　community　compared　with　that　of　the　rhizosphere　effect.　©　2019　FEMS　2019.