Abstract: A rapid determination method for amantadine and rimantadine in animal tissues was established using liquid chromatography-electrospray tandem mass spectrometry(LC-ESIMS/MS) in the multiple reaction monitoring (MRM) mode. The samples were extracted with acetonitrile 1.0% trichloroacetic acid（50∶50，V/V） solution in ultrasonic， followed by a cleanup procedure with mixed cation exchange SPE. The eluate was dried under nitrogen blow, then dissolved in 1 mL methanol-0.2% formic acid(10∶90, V/V) solution and the aliquot was detected by LC-MS/MS. The chromatographic retention time and mass fragment ion abundance ratio were taken for qualitative confirmation, and external standard method was employed for quantification. The limit of detection (LOD) is 0.4 μg/kg, and the limit of quantification (LOQ) is 1.0 μg/kg in chicken, chicken liver, pork and pork liver. The correlation coefficent is greater than 0.999(r₂＞0.999) of the four animal tissues are obtained within 0.5—100.0 μg/L linear ranges. Recoveries are in a range of 70.7%—92.3% with the relative standard deviations (RSDs) varied from 1.7% to 11.7% at spiked levels of 5.0—100μg/kg, respectively.