OBJECTIVE： To study the serum pharmacochemistry of Huafengdan， and to investigate its active component base preliminarily. METHODS： UPLC-Q-TOF/MS was used to establish the fingerprints of Huafengdan and drug-containing serum of rats after intragastric administration of extract of Huafengdan （6 g/kg）， Yaomu （1.37 g/kg） and Yaomu negative sample （5.73 g/kg）. The fingerprints of Huafengdan and drug-containing serum were compared under positive and negative ion model， in order to preliminarily indentify the components absorbed into blood and metabolites of Huafengdan. RESULTS： Under negative ion model， 8 drug-induced constituents （3 prototype components， 5 possible metabolites） were found in drug-containing serum， 6 of which were from Yaomu. Under positive ion model， 9 drug-induced constituents （2 prototype components， 7 possible metabolites） were found in drug-containing serum， 6 of which were from Yaomu. CONCLUSIONS： The components absorbed into blood of Huafengdan are confirmed preliminarily and mainly come from Yaomu.