A rapid resolution liquid chromatography coupled with quadrupole-time-of-flight mass spectrometric (RRLC-Q-TOF-MS) method was established and optimized for the analysis of pharmacokinetic behavior of ginsenoside Rb2 in rats by intravenous injection administration.The metabolism of ginsenosides Rb2 in vivo rat was also explored.In the experiment,Agilent SB C18 column was selected for the sample separation with 0.1％ aqueous formic acid solution as mobile phase (A) and acetonitrile as mobile phase (B) at a flow rate of 0.2 mL/min,and the injection volume was set to 5 μL.Q-TOF-MS was carried out in electron pray ionization (ESI) negative ion mode.The limit of quantification (LOQ,S/N =10) and limit of detection (LOD,S/N=3) were 0.10 and 0.08 μg/mL,respectively,and the linear range was 0.1-1.26 μg/mL.The experiment results showed that the concentration-time profile of ginsenoside Rb2 conformed to a two-compartment pharmacokinetic model after intravenous administration for rats.The mean plasma elimination half-lives were (23.58±1.10) min (t1/2α),(1306.55±147.23) min (t1/2β) for Rb2.By analyzing the urine of rats after intravenous administration and the fecal samples after oral administration of ginsenoside Rb2,it was found that the metabolites were M6,M2 (CY),F2,and C-K.