Objective To research the relationship between the expression of PAI-1 and the clinical characteristics of the endometrial carcinoma.Methods We detected the level of the serum PAI-1 by ELISA in the patients with endometrial carcinoma,the patients with endometrial hyperplasia and the patients with normal endometrium.The expression of PAI-1 in endometrial carcinoma and normal endometrial tissues was observed by immunohistochemistry.Results The concentration of serum PAI-1 in patients with endometrial carcinoma was 18.64 ± 6.22 μtg/L,significantly higher than those of patients with endometrial hyperplasia (6.94 ± 2.87) μg/L and patients with normal endometrium (6.68 ± 2.13)μg/L (P=0.00).The expression rate of PAI-1 was 68.2％ (15/22) in endometrial carcinoma tissue,and 8.3％ (2/24) in normal endometrial tissue (P=0.00).Compared with the early endometrial carcinoma,the expression rate of PAI-1 in the advanced endometrial carcinoma was significantly higher (6/6 w 9/16,P=0.03).Conclusions The expression level of PAI-1 may be related to the stage of the endometrial carcinoma.