To compare the approaching degree of the expression of NO, vWF and 6-keto-PGF1a between Yang-Tonifying Five-Returning Decoction(YFD) contained plasma and serum on brain microvascular endothelial cells(BMECs)injured by hypoxia rats with true value of animals in vivo experiments, and to provide references for selecting plasma or serum in the study of ex vivo experiments.Methods:The model of MCAO was made by Suture Embolization Method in the internal carotid artery of rats. BMECs were made in hypoxia incubator. The method of Enzyme-linked immunosorbent(ELISA)was used to measure the expression of NO, vWF and 6-keto-PGF1a.Results:Both of medicated plasma and medicated serum of YFD could significantly reduce the content of vWF, increase the expression of NO and 6-keto-PGF1a. There were significant differences(P<0.05 orP<0.01）compared with blank plasma and blank serum; The correlation coefficients of vWF between medicated plasma and in vivo experiments was higher than those between medicated serum and in vivo experiments. There was significant difference.The correlation coefficients of NO and 6-keto-PGF1a between medicated plasma and in vivo experiments were in close proximity to those between medicated serum and in vivo experiments. There were no significant differences.Conclusion:When studying the expression of vWF in the ex vivo experiment, it is suggested that the plasma pharmacology method should be used. When studying the expression of NO and 6-keto-PGF1a, the methods of plasma pharmacology and serum pharmacology can be both selected.