A analytical method was developed for the simultaneous determination of fifteen rodenticides in whole blood and urine samples by liquid chromatography-tandem mass spectrometry(LC-MS/MS) with on-line solid phase extraction(on-line SPE).The samples were treated with acetonitrile,followed by dilution,centrifugation and filtration.The solution obtained was purified with a polymer column for hydrophilic-lipophilic balance(HLB),then eluted on a ZORBAX Eclipse Plus C18 column with acetonitrile and 0.01 mol/L ammonium acetate aqueous solution as mobile phase.The analytes were detected in dynamic multiple reaction monitoring(DMRM) mode under alternate positive/negative electrospray ionization(ESI+/ESI-) mode,and quantified by external standard method.The results showed that there existed good linear relationships by quadratic equation fitting for the fifteen rodenticides in whole blood and urine in the investigated mass concentration ranges with the correlation coefficients not less than 0.997 8 for whole blood and not less than 0.996 5 for urine,respectively.The LODs and the LOQs varied from 0.10 μg/L to 5.00 μg/L and 0.50 μg/L to 10.0 μg/L,respectively.The recoveries at three spiked levels in whole blood and urine ranged from 81.8% to 109.6% with their RSDs of 0.3%-3.8%(n=6).The developed method is simple and reliable,and is sensitive for the rapid detection and accurate quantification of fifteen rodenticides in whole blood and urine samples.