Abstract: To study the changes in the pharmacokinetic behavior of four coumarins (bergapten, oxypeucedanin, imperatorin and isoimperatorin) in rats before and after combinating Angelicae Dahuricae Radix with Chuanxiong Rhizoma. The plasma concentrations of the drugs were determined by ultra performance liquid chromatography-fluorescence detection (UPLC-FLD) for dose response and time dependent curves. The pharmacokinetic parameters were calculated by DAS 3.2.8, and SPSS 20.0 was used to analyze the differences of main pharmacokinetic parameters between the two groups. The result showed:comparing with Angelicae Dahuricae Radix group, the area under drug time curve (AUC_{0-24 h}) of bergapten, oxypeucedanin and imperatorin increased by 177.2%, 97.14% and 54.43% respectively, AUC_0-∞ increased by 282.3%, 104.2%, and 75.40% respectively, and clearance rate (CL_Z/F) decreased by 68.26%, 51.08% and 43.98% respectively; the peak drug concentration (C_max) of four coumarins was significantly increased; the distribution volume (V_Z/F) of bergapten was significantly decreased. These data indicated that Chuanxiong Rhizoma can promote the absorption of coumarins in Angelicae Dahuricae Radix, slow down the elimination of coumarins, and increase their bioavailability in vivo. The animal experiment scheme in this study has been approved by the Experimental Animal Ethics Committee of Beijing University of Chinese Medicine (approval number:BUCM-4-2020083105-3072).