Abstract: Objective To investigate the expressions of Livin and phosphate and tension homology deleted on chromsome ten (PTEN) protein in the cancerous tissues of ovary endometriosis. Methods Immunohistochemistry EliVision was used to examine the expressions of Livin and PETN protein in 19 samples of ovary endometriosis cancerous tissues, 30 samples of ovary endometriosis tissues and 30 samples of ovarian benign tumor tissues. Results The positive expression rate of Livin in ovary endometriosis cancerous tissues (68%) was obviously higher than that in ovary endometriosis tissues (36%) and benign tumor tissues (13%)（ P<0.05）. The positive expression rate of PTEN in ovary endometriosis cancerous tissues (16%) was obviously lower than that in ovary endometriosis tissues (65%) and benign tumor tissues (80%)（ P<0.01）. There was no correlations between positive expressions of Livin and age, clinical stage, grading, histological type and lymphatic metastasis of ovary endometriosis cancer ( P>0.05), the same result was also found for PTEN. Livin and PTEN expression presented an obviously negative correlation in ovary endometriosis cancer ( r=-0.559， P=0.001). Conclusion Up-regulation of Livin expression and down-regulation of PTEN may be involved in the occurrence and development of ovary endometriosis cancerization.