A method was established for the rapid determination of 11 algal toxins in sediments by ultra performance liquid chromatography - tandem mass spectrometry.Firstly，the sample was freezingly dried out，and then sieved，followed by purification with 0.1 mol/L EDTA-Na4P2O7 solution and HLB solid phase extraction column，elution with methanol-0.2% formic acid，and finally concentrated and mixed with nitrogen to 1 mL.The separation of the analyte was performed on a Waters BEH C18 chromatographic column with acetonitrile -0.2% formic acid solution as mobile phase by gradient elution.The sample was analyzed by ultra performance liquid chromatography-tandem mass spectrometry in positive ions electrospray mode under multi-stage monitoring mode (MRM)，and quantified by external standard method.The results showed that the detection limits for 11 algal toxins in sediment were in the range of 1.0-5.0 ng/kg.The average recoveries for the same environmental samples at three spiked concentrations of 0.1，1.0，4.0 μg/kg were in the range of 70.3%-112.5% with relative standard deviations of 2.2%-9.3%.The method was rapid，sensitive and accurate，and could be effectively applied in the rapid monitoring of 11 algal toxins in sediments.A method was established for the rapid determination of 11 algal toxins in sediments by ultra performance liquid chromatography - tandem mass spectrometry.Firstly，the sample was freezingly dried out，and then sieved，followed by purification with 0.1 mol/L EDTA-Na4P2O7 solution and HLB solid phase extraction column，elution with methanol-0.2% formic acid，and finally concentrated and mixed with nitrogen to 1 mL.The separation of the analyte was performed on a Waters BEH C18 chromatographic column with acetonitrile -0.2% formic acid solution as mobile phase by gradient elution.The sample was analyzed by ultra performance liquid chromatography-tandem mass spectrometry in positive ions electrospray mode under multi-stage monitoring mode (MRM)，and quantified by external standard method.The results showed that the detection limits for 11 algal toxins in sediment were in the range of 1.0-5.0 ng/kg.The average recoveries for the same environmental samples at three spiked concentrations of 0.1，1.0，4.0 μg/kg were in the range of 70.3%-112.5% with relative standard deviations of 2.2%-9.3%.The method was rapid，sensitive and accurate，and could be effectively applied in the rapid monitoring of 11 algal toxins in sediments.A method was established for the rapid determination of 11 algal toxins in sediments by ultra performance liquid chromatography - tandem mass spectrometry.Firstly，the sample was freezingly dried out，and then sieved，followed by purification with 0.1 mol/L EDTA-Na4P2O7 solution and HLB solid phase extraction column，elution with methanol-0.2% formic acid，and finally concentrated and mixed with nitrogen to 1 mL.The separation of the analyte was performed on a Waters BEH C18 chromatographic column with acetonitrile -0.2% formic acid solution as mobile phase by gradient elution.The sample was analyzed by ultra performance liquid chromatography-tandem mass spectrometry in positive ions electrospray mode under multi-stage monitoring mode (MRM)，and quantified by external standard method.The results showed that the detection limits for 11 algal toxins in sediment were in the range of 1.0-5.0 ng/kg.The average recoveries for the same environmental samples at three spiked concentrations of 0.1，1.0，4.0 μg/kg were in the range of 70.3%-112.5% with relative standard deviations of 2.2%-9.3%.The method was rapid，sensitive and accurate，and could be effectively applied in the rapid monitoring of 11 algal toxins in sediments.