Abstract: To profile and characterize the ingredients absorbed into blood and their metabolites of the Eucommiae Cortex (EC) extracts in rats with renal fibrosis induced by adenine, and so as to provide a reference for investigation of the pharmacodynamic substances of EC. SD rats with renal fibrosis induced by adenine were intragastrically administered with the EC extracts, and the rat plasma samples were collected and analyzed by UHPLC-Q-TOF-MS/MS to identify the prototype ingredients absorbed into blood and their metabolites. The experiment was approved by the experimental Animal Ethics Committee from Nanjing University of Chinese Medicine (No. 202103A008). The results showed that a total of 24 prototype compounds were identified, including 9 lignans, 4 iridoids, 8 phenylpropanoids, and 3 organic acids. Furthermore, 30 metabolites were obtained by further analysis, including 9 lignans, 19 iridoids, and 2 organic acids. The results of this study can provide the valuable reference for further elucidation of the pharmacodynamic substantial basis and mechanism of EC in the treatment of renal fibrosis.