Objective: To investigate the clinical significance of matrix metalloproteinase 2、9(MMP2、MMP9) in endometriosis.Method: The expression of MMP2 MMP9 protein were determined by immunohistochemical method and geltin in cultured endometriotic cells with median(controls) or with tumor necrosis factor-α(TNF-α).The endometriotic tissues were sourced from 16 patients with endometriosis.Meanwhile the MMP2、MMP9 protein content of cultured supematent was also measured.Result: Endometriotic stromal cells continualy expressed MMP2、MMP9,after exposured to TNF-α,the expression of MMP9 protein in the endometriotic cells was statisticaly higher compared with control group(P0.05),so was the MMP9 protein content of supermatent.However,we did not find difference in MMP2 between the two groups.Conclusion: TNF-α can up-regulate the expression of MMP-9 in endometriotic cells,which may be related to the development of endometriosis.