In　order　to　investigate　the　application　of　the　floating　bed　and　explore　the　effective　measures　for　agricultural　non-point　source　pollution　control,　five　kinds　of　local　plants　(Canna　indica,　Lythrum　salicaria,　Iris　pseudacorus,　Ipomoea　aquatica　and　Oryza　sativa)　were　cultivated　on　the　floating-bed　in　the　return　flow　ditches　of　rice　paddy　to　compare　their　removal　effects　of　nitrogen　and　phosphorus.　The　results　showed　that　the　biomass　of　the　five　kinds　of　floating　bed　plants　increased　significantly　in　the　return　flow　of　rice　paddy　for　four　months　cultivation.　The　biomass　growth　of　Canna　indica　was　the　largest,　which　was　97.2　g•plant-1,　and　it　was　followed　by　Lythrum　salicaria　with　81.3　g•plant-1.　The　survival　rate　of　Ipomoea　aquatica　was　the　highest　with　a　value　of　91.67%,　and　it　was　followed　by　Canna　indica　with　87.50%,　while　the　survival　rate　of　Oryza　sativa　was　the　lowest　with　a　value　of　only　60.71%.　The　total　nitrogen　concentrations　in　stems/leaves　and　roots　of　Lythrum　salicaria　were　the　highest,　which　were　0.85%　and　0.65%,　respectively.　The　total　phosphorus　concentrations　in　stems/leaves　and　roots　of　Canna　indica　were　the　highest,　which　were　0.15%　and　0.17%,　respectively.　The　largest　nitrogen　uptake　amount　occurred　in　Ipomoea　aquatica　with　a　value　of　14　239.46　mg•m-2,　which　was　followed　by　Canna　indica　with　10　798.00　mg•m-2.　The　largest　phosphorus　uptake　amount　occurred　in　Oryza　sativa　with　a　value　of　407.11　mg•m-2,　which　was　followed　by　Ipomoea　aquatica　with　374.41　mg•m-2.　The　total　nitrogen　(TN)　removal　efficiency　in　the　return　flow　of　rice　paddy　by　Ipomoea　aquatica　was　the　highest　with　a　value　of　85.88%,　which　was　followed　by　Canna　indica　with　81.67%.　The　total　phosphorus　(TP)　removal　efficiency　in　the　return　flow　of　rice　paddy　by　Ipomoea　aquatica　was　the　highest　with　a　value　of　80.32%,　which　was　followed　by　Oryza　sativa　with　72.86%.　Therefore,　Ipomoea　aquatica　and　Canna　indica　cultivated　on　floating-bed　were　recommended　as　the　main　plants　for　improving　the　water　quality　of　farmland　drainage　ditch　in　Ningxia　yellow　river　irrigation　region.　©　2019,　Science　Press.　All　right　reserved.