Abstract: OBJECTIVE To investigate the components and metabolites of leaves of Cyclocarya paliurus in rats plasma. METHODS UHPLC-Q/TOF-MS method was applied to identify the components and metabolites of rat plasma. The prototype components and metabolites were analyzed in rats plasma of leaves of Cyclocarya paliurus water extract after intragastric administration by comparing the chromatograms of Cyclocarya paliurus, blank serum and drug-containing serum. RESULTS A total of 15 compounds including 6 prototype components and 9 metabolites were identified. The main prototype components in blood were caffeylquinic acid, flavonoids and saponins, and the metabolic pathways were methylation and hydroxylation. CONCLUSION This experiment showes that the prototype components absorbed into blood may be the potential bioactive components in leaves of Cyclocarya paliurus, providing a scientific basis for clarifying its material basis in pharmacodynamics.