Objective To investigate the mechanism of Xuefu Zhuyu Decoction （Decoction for removing blood stasis in the chest） in promoting the endothelia-derived angiogenesis. Methods Twelve SD rats were randomized into Xuefu Zhuyu Decoction group and blank control group with 6 in each. The medicine-containing serum with the Xuefu Zhuyu Decoction ingredients in it and the blank control serum were prepared respectively. By using a serum pharmacology technique

the 1.25%

2.5%

and 5% concentrations of Xuefu Zhuyu Decoction containing serum and the blank control serum were adopted for endothelial cell incubation for 48h. The effect on the reproduction

migration

and in vitro vasoformation of endothelial cells ECV304 were examined. Moreover

the nitric oxide （NO） concentration in the cultured supernate was evaluated

the intracellular NO concentration and endothelial nitric oxide synthetase （eNOS） activity were studied

and the eNOS expression was determined. Results Compared with the same concentration serum of the blank control group

the reproduction of cells under the condition of low （1.25%） and medium （2.5%） concentrations of medicine-containing serum was significantly increased （P<0.05）

the migration of cells under the condition of medium （2.5%） and high （5%） concentrations of medicine-containing serum was significantly increased （P<0.01）. The lumens under the condition of all concentrations of medicine-containing serum were significantly increased （P<0.01）. All concentrations of medicinal serum could increase the endothelia-derived intracellular and extracellular NO concentrations and the eNOS expression （P<0.05 or P<0.01）. And the 1.25% and 2.5% concentrations of medicine-containing serum could enhance the eNOS activity as well （P<0.05 or P<0.01）. Conclusion Xuefu Zhuyu Decoction increases the intracellular and extracellular NO concentration of gas to promote angiogenesis through improving the eNOS expression and activity.