Objective:To observe the expressions of claudin-4 and claudin-1 in endometrial cancer and explore their correlations with clinicopathological parameters of endometrial cancer.Methods:Immunohistochemical methods（SP） were used to detect the expressions of claudin-4 and claudin-1 in 52 tissue samples of endometrial cancer

24 of atypical hyperplasia

20 of pericancerous endometrium

and 19 of endometrium at proliferative phase.And then the expressions were analyzed statistically to find out the correlations with clinicopathological parameters of endometrial cancer.Results:Positive rate of claudin-4 was 36.8%

70.8% and 90.4% in endometrium at proliferative phase

atypical hyperplasia and endometrial cancer

respectively

with significantly differences between them（P<0.05）

and it was statistically different between pericancer endometrium and endometrial cancer（P<0.05）.Positive rate of claudin-1 was 89.5%

66.7% and 63.5%

respectively showing a descending tendency and significantly differences between endometrium at proliferative phase and endometrial caner（P<0.05）

and it was also statistically significantly different between pericancer endometrium and endometrial cancer（P<0.05）.The high expression rate of claudin-4 was related to invasion depth

but not to histological grading

pathological staging or lymph node metastasis of endometrial cancer

and the low expression of claudin-1 in endometrial cancer was not associated with histological grading

pathological staging

invasion depth or lymph node metastasis.Conclusion:The expression levels of claudin-4 and claudin-1 are correlated with onset and development of endometrial cancer.