Abstract: Objective :To study the significance of expression of the catalytic subunit ofhuman telomerase hTERT and apoptosis related protein (bcl-2, casperse-3) in borderline epithelialovarian tumors. Meth-ods :Forty-one cuses of borderline epithelial ovarian tumors were studiedwhich were admitted to the Tianjin Cancer Institute and Hospital. hTERT, bcl-2 and casperse-3were analyzed using immunohistochemistry in formalin-fixed paraffin-embedded tissue. Their statuswere compared to twenty-two benign and thirty malignant tumors. Results :(1) Of the borderlineovarian tumors, the positive expression rate of hTERT was 46.3% which was significantly lowerthan those of malignant(73.3%)tumors ( P=0.023), but the difference between the borderline andbenign ovarian tumors was not significant (P=0.446).(2) Of the borderline ovarian tumors, the positive expression rate of bcl-2 and casperse-3 was 58.5%and 73.2%, while in the benign andmalignant tumors was 59.1%and 72.7%, 86.7% and 43.3%, respectively. Compared to borerlinetumors ,the expression rate of bcl-2 and casperse-3 in malignant tumors was significantly higheror lower(P=0.010, 0.011), but there was no correlation between expressions of bcl-2 and casperse-3in borderline ovarian tumors(r=-0.063, P>0.05).And the differences of them between benign and borderline tumors were not signifieant CP=0.966, 0.970). (3) Of the ninety-threeovanan tumors,there was no correlation between expressions of hTERT and bcl-2(r=0.037, P>0.05):but therewas significantly reverse correlation between expressions of hTERT and casperse-3 (r=-0.227, P<0.05). Conclusion :These data suggest that detecting hTERT may reflect elomerase activity andthe level of hTERTmRNA,co-examination of hTERT and apoptosis related protein (bcl-2 and casperse-3) may contribute to estimating the malignant potential of borderline ovarian tumors. Sothey possibly become new markers to distinguish a subpopulation with the potential to develop invasive carcinomas.