Abstract: Objective：To study the expression changes of interleukin-8 (IL-8) mRNA, matrix metalloproteinase 9 (MMP-9) and vascular endothelial growth factor (VEGF) in eutopic endometrium of patients with endometriosis (EMs), and to confirm that it is involved in the occurrence and development of EMs. Methods：IL-8 mRNA, MMP-9 and VEGF protein expression in eutopic endometrium of EMs patients before and after treatment and the healthy control group were detected. Results：The expression of IL-8 mRNA in EMs group before treated was higher than that in control group, and the expression of IL-8 mRNA was decreased after treatment (both P＜0.05). Positive expression rate of MMP-9 and VEGF protein in endometriosis patients before treated were higher than that of the control group and the patients after treatment (P＜0.05). IL-8 mRNA and MMP-9 protein expression and VEGF protein expression existed positive correlation (rs=0.842, 0.851, all P＜0.05). Conclusions：Complete surgical excision of endometriosis lesions combined with drug therapy can improve the microenvironment of endometriosis and to delay its recurrence. IL-8, MMP-9 and VEGF had synergistic effect in endometriosis occurrence and development.

Key words: Endometriosis, Endometrium, Interleukin-8, Matrix metalloproteinase 9, Vascular endothelial growth factor