To determine the 3 components of Cortex Eucommiae by ultra-high performance liquid chromatography combined with mass spectrometry and their pharmacokinetics.Methods:Electrospray ionization source(ESI)was used to monitor the monitoring ions of geniposide chlorogenic acid and terpineol diglucoside，and internal standards for quantitative analysis of geniposide chlorogenic acid and terpineol diglucoside.Results:1)The 3 index components of Cortex Eucommiae such as geniposide，chlorogenic acid and terpineol diglucoside，were well separated and had no interference of endogenous substances，with good specificity.2)The UPLC method was rigorous，and its precision，stability test，repeatability test and sample recovery rate were all good.3)The pharmacokinetics of geniposide and turpentine diglucoside in rats was nonlinear，but only chlorogenic acid was linear.However，there were significant differences in the 2 parameters of CLz and Vz，indicating that the pharmacokinetic metabolism of the 3 components of Cortex Eucommiae extract in rat plasma was inconsistent.Conclusion:The operation of UPLC-MS/MS is simple，and the results have good precision，stability and reproducibility.It can be used as a reliable method for the study of effective components and pharmacokinetics of Cortex Eucommiae.