Abstract: Objective To investigate the expression and clinical significance of matrix met-alloproteinases-9 (MMP-9)in tissues of endometrial carcinoma.Methods The paraffin samples of tissues in 30 patients with endometrial carcinoma admitted in our hospital from February 2009 to March 2012 were selected as experimental group 1 while those in other 40 patients with atypical en-dometrial hyperplasia and 40 healthy people as experimental group 2 and control group,respective-ly.Immunohistochemical staining method was used for the MMP-9 staining so as to analyze the counts of cells with positive staining and the staining severity.MMP-9 expression levels were com-pared,the relationship between MMP-9 expression and clinical pathological parameters in endome-trial carcinoma tissues were analyzed and Cox ratio risk model was applied to analyze the prognostic factors of endometrial carcinoma.Results Experimental group 1 was evidently lower in low-expres-sion of MMP-9 than experimental group 2 and apparently higher in high-expression of MMP-9 than the other groups (P <0.05).It was showed that pathological staging and lumph node metastasis were closely associated with MMP-9 protein expression (P <0.05),which were also the risk fac-tors impacting the prognosis of endometrial carcinoma (P <0.05).Conclusion The specific high-expression of MMP-9 in endometrial carcinoma can be considered as one of the referent indexes for diagnosing endometrial carcinoma and its pathological staging,which,however,is not the indepen-dent risk factor influencing the prognosis of endometrial carcinoma.