Purpose To investigate the expression and clinical significance of Foxp3 ( cell surface marker of regulatroy T) mRNA and its protein in endometrial carcinomas and normal endometrial tissues. Methods Real-time fluorescence quantitative PCR and immuno-histochemical SP methods were used to detect the expressions of mRNA and protein in tumor tissue of 84 cases of endometrial carcino-mas and 40 cases of normal endometrial tissue, then to analyze the relationship between Foxp3 gene and clinical pathological character-istics of endometrial carcinoma specimens, such as differentiation, FIGO stage. Results Foxp3 mRNA and it′s protein expression of endometrial carcinomas were significantly higher than that of normal endometrial tissues. There were significantly relationships between Foxp3 mRNA expression and FIGO stage of endometrial cancer, Foxp3 mRNA expressions of III+IV stage was higher than that ofⅠ+Ⅱ stage endometrial carcinoma (P<0. 05). But the relationship between Foxp3 expression and differentiation degree reached differ-ent conclusions in the two detection methods. By immunohistochemistry the expression of Foxp3 protein was correlation with histological differentiation grade (rs =0. 72, P <0. 01). In poorly differentiated endometrial carcinoma Foxp3 + cell number was significantly higher than that in well differentiated endometrial carcinoma. By detection of real-time fluorescence quantitative PCR method, Foxp3 mRNA expression was not correlated with tumor grade (rs =0. 01, P=0. 35). Conclusion Foxp3 in endometrial carcinomas are high expressions. Immunohistochemical method has more clinical value than real-time fluorescence quantitative PCR test results. Foxp3 may be involved in the regulation of the development of endometrial cancers.