Objective To evaluate the effect of different doses of Astragalus membranaceus on the levels of vascular endothelial growth factor ( VEGF) and basic fibroblast growth factor ( bFGF) in serum and lung tissues of rats with pulmonary embolism. Methods Seventy-six clean-grade healthy male Sprague-Dawley rats, aged 8-9 weeks, weighing 140-170 g, were assigned to control group ( group C, n=11) and experimental group ( group E, n=65) by a random number table method. The rats with pulmonary em-bolism in group E were further divided into 4 subgroups using a random number table method: pulmonary embolism group (group P), low-dose Astragalus membranaceus group (group H1), median-dose Astraga-lus membranaceus group ( group H2 ) and high-dose Astragalus membranaceus group ( group H3 ) . The model of pulmonary embolism was established by injecting autologous blood clots into the right jugular vein. At 1 h and 1, 2, 3, 4, 5 and 6 days after successful establishment of the model, Astragalus membrana-ceus 20, 40 and 60 g∕kg were injected intraperitoneally in H1-3 groups, respectively, while the equal vol-ume of normal saline was given instead in group P. The chest was opened after anesthesia on day 7, and blood samples were collected from cardiac chambers for determination of concentrations of serum VEGF and bFGF by enzyme-linked immunosorbent assay. The pulmonary specimens were obtained from the upper lobe of right lungs for determination of the expression of VEGF and bFGF mRNA ( using real-time polymerase chain reaction) . Results Compared with group C, the concentrations of serum VEGF and bFGF were sig-nificantly increased, and the expression of VEGF and bFGF mRNA in lung tissues was up-regulated in the other four groups (P<0. 05). Compared with group P, the serum bFGF concentration was significantly in-creased, and the expression of VEGF and bFGF mRNA in lung tissues was up-regulated in H1-3 groups ( P<0. 05) . Compared with group H1, the serum bFGF concentration was significantly increased, the ex-pression of VEGF mRNA and bFGF mRNA in lung tissues was up-regulated in H2 and H3 groups ( P<0. 05) . Compared with group H2, the expression of VEGF and bFGF mRNA in lung tissues was significant-ly up-regulated in group H3 ( P<0. 05 ) . Conclusion Astragalus membranaceus can up-regulate the ex-pression of VEGF and bFGF in lung tissues in a dose-dependent manner, thus improving pulmonary embol-ism in rats.