Objective: To study the effect and mechanism of Yangxue Huayu Xiaozheng decoction on formation of endometriosis foci in rats. Method: Female SD rats were selected and all the other rats except 10 rats in normal group were used to establish endometriosis models with auto grafting method. The successfully modeled rats were randomly divided into six groups

including model group

Yangxue Huayu Xiaozheng decoction high-dose group

middle-dose group

low-dose group (12

8

4 g·kg-1

respectively) and Gestrinone group (0.05 g·kg-1)

n=10 in each group. After ig administration respectively for 28 days

the lesion tissue samples of rats were collected

and the inhibitory effect of Yangxue Huayu Xiaozheng decoction on endometriosis tissue in rats was observed. The expression of vascular endothelial growth factor (VEGF) and vascular endothelial growth factor receptor1 (VEGFR-1) were detected in ectopic endometrium by using RT-PCR and Western blot technique. Result: Compared with the normal group

the expression of VEGF and VEGFR-1 mRNA and protein in endometriosis tissues of rats in model group was significantly higher (P<0.05). Compared with the model group

endometriosis tissues of rats in drug groups were significantly inhibited

and the expression of VEGF and VEGFR-1 mRNA and protein in endometriosis tissues of rats in various drug groups was significantly lower than that in model group (P<0.05). Conclusion: Yangxue Huayu Xiaozheng decoction could obviously inhibit the development of endometriosis tissues in model rats. It may have a closely relation with the inhibition of VEGF/VEGFR signaling pathway to regulate the angiogenesis of lesions.