Abstract: Objective : To investigate expression and diagnostic significance of mitochondrial crea-tine kinase (CIA-mit), and anti-Iii-67 nuclear antigen Ki-67) in endometrioid carcinoma. Methods :Expression of CIA-mit and Iii-67 were detected in 70 cases endometrioid carcinoma and 10 cases en-dometrioid dysplasia and 20 cases endometrial hyperplasia by using SP immunohistochemical staining. Results :CIA-mit and Ki-67 all have high level expression in endometrioid carcinoma. The more poor-ly differentiated carcinoma showed the more highly expression. The expression of CIA-mit and Ki-67 isdifferent significantly between endometrioid carcinoma and endometrial hyperplasia (P<0.01), betweenendometrial dysplasia and endometrial hyperplasia (P<0.05), not between endometrial hyperplasia andendometrial d ysplasia. Conclusions : The expression of CIA-mit and Iii-67 index increase with the de-ceased histological differentiation in endomaetrioid carcinoma. Statistic difference exist between en-dometrioid carcinoma and endometrioal hyperplasia, but not between endometrioid carcinoma and en-dometrial displasia. It is suggested that endometrioid diasplasia is precarcinomatous lesions and thatover expression of CIA-mit and Iii-67 may play an important role in the development of endomaetrioidcarcinoma. The examination of CIA-mit and Ki-67 is significant for the diagnosis, early detection and prognosis determination of endometrioid carcinoma.