To　research　the　mechanisms　of　Fe　transport　and　cycling　in　wetland-based　aquaculture　ponds.　In　this　study,　the　abundance　and　speciation　of　reactive　Fe　in　sediments　of　four　wetland-based　shrimp　ponds　in　three　estuaries　of　Fujian　Province,　southeast　China,　were　investigated　during　the　intensive　culture　period.　Significant　differences　of　crystalline　Fe(III),　non-sulfidic　Fe(II),　organic　Fe-complex,　and　Fe　sulfides　were　observed　among　the　four　shrimp　ponds.　Porewater　Cl-　and　SO42-　were　key　factors　affecting　the　abundance　and　speciation　of　Fe　among　different　shrimp　ponds.　Along　with　increasing　salinity,　the　contents　of　Fe　sulfides　increased,　whereas　those　of　organic　Fe-complexes　and　crystalline　Fe(III)　decreased.　The　contents　of　reactive　Fe　were　in　the　following　order:　solid-phase　Fe　(III)　＞　Fe　sulfides　＞　non-sulfidic　Fe　(II)　＞　organic　Fe　complexes.　The　contents　of　FeS　and　FeS2　were　higher　in　the　subsurface　sediments　of　the　shrimp　ponds　than　those　in　the　surface　sediments.However,　the　contents　of　organic　Fe　complexes　and　concentrations　of　porewater　SO42-　and　NH4+　were　higher　in　the　surface　sediments　than　those　in　the　subsurface　sediments.　The　precipitation　of　Fe　sulfides　could　partially　reduce　the　potential　risk　of　nutrient　contamination　in　sediments　of　wetland-based　shrimp　ponds.　©　2019,　Editorial　Board　of　China　Environmental　Science.　All　right　reserved.