A rapid and sensitive Ultra high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed for the simultaneous determination of fourteen alkaloids in beagle dog plasma after a single oral dose of the () extract selected bifendate as the internal standard (IS). The plasma samples were preprocessed by liquid-liquid extraction (LLE) with aether before separation on an Agilent SB-C column (1.8 µm, 150 × 2.1 mm) using a gradient elution program. The mobile phase consists of 0.2% acetic acid and acetonitrile at the flow rate of 0.3 mL/min. In the positive ion mode, the analytes were detected by multiple reaction monitoring (MRM). The results indicated that calibration curves for fourteen analytes have good linearity (² = 0.9904). The lower limits of quantification (LLOQ) of fourteen alkaloids and IS were all over 4.87 ng/mL and the matrix effects ranged from 94.08% to 102.76%. The mean extraction recoveries of Quality control samples at low (LQC), medium (MQC) and high (HQC) and IS were all more than 78.03%. The intra- and inter-day precision (R.S.D.%) also met the criterion, at the same time the deviation of assay accuracies (R.E) ranged from -13.70% to 14.40%. The values of fourteen alkaloids were no more than 1 h. The range of was from 74.16 ± 8.71 to 2256 ± 255.9 ng/mL. The assay was validated in the light of the regulatory bioanalytical guidelines and proved acceptable, which was successfully applied to a pharmacokinetic study of these compounds in beagle dogs after oral administration of extract.