Objective To investigate the expression of phosphorylation-mammalian target of rapamycin (p-mTOR) in endometrial carcinoma. Methods The expressions of p-mTOR protein in tissues from 45 cases of endometrial adenocarcinoma, 7 endometrial atypical hyperplasia, and 6 normal endometrium were detected by immunohistochemistry SP method. Results The expression of p-mTOR protein maily restricted to cytoplasm. Compared with normal endometrium, the expression of p-mTOR protein in the cases of endometrial atypical hyperplasia and endometrial adenocarcinoma was significantly up-regulation(2.36 ± 0.76vs 6.21 ± 1.19, 15.82 ± 2.64)( F = 11.37, P ＜ 0.05 ). There was significant difference of p-mTOR protein in different histology class in endometrial adenocarcinoma (F = 8.27, P ＜ 0.05), but there was no significant difference of p-mTOR protein in different pathological grade in endometrial adenocarcinoma (P ＞0.05).Conclusion The expression of p-mTOR protein may participate in the occurrence and development of endometrial carcinoma.