Objective To evaluate the intestinal absorption of main components (paeoniflorin,ferulic acid,narirutin,naringin,neohesperidin,and glycyrrhizic acid) in aqueous extract of Chaihu Shugan San (CSS).Methods UPLC method was established to simultaneously determine the concentrations of the six components in the test samples of everted gut sacs and in situ single pass intestinal perfusion (SPIP) models.Absorption kinetics parameters were calculated for describing their absorption characteristics.Results In SPIP model,the results indicated that ferulic acid was the well-absorbed ingredient in whole small intestine,while other ingredients presented moderate or poor absorption.In everted gut sacs model,paeoniflorin in jejunum,ferulic acid,naringin,and neohesperidin in duodenum,narirutin in duodenum and jejunum,had the best absorption,while there was no significant difference in absorption of glycyrrhizic acid in the intestine.Condusion In vivo model indicated that the main constituents in CSS could be absorbed in intestinal wall of rat,ferulic acid could be much more easily penetrated intestinal wall into the blood circulation than the other five components.Ex vivo model could further articulate that six index components could be absorbed selectively in different intestinal segments.