Abstract: Objective To investigate the expression and clinical significance of Numb and P53 proteins in epithelial ovarian carcinoma. Methods We co-tested the expressions of Numb and P53 proteins in epithelial ovarian tissues by immunohistochemistry, including 20 cases of normal tissues, 29 cases of benign tumors, 35 cases of borderline ovarian tumors and 87 cases of epithelial ovarian carcinoma. Their clinical significance was analyzed. Results The positive expression rates of Numb protein in normal ovarian tissues, benign ovarian tumors, borderline ovarian tumors and epithelial ovarian carcinoma were 5%, 13.8%, 51.4% and 70.1%, respectively, and with the rising trend and significantly difference among four groups ( P<0.05). The expression of Numb protein had significant positive correlation with stage and lymph node metastasis ( P<0.05), while Numb expression had no correlation with age, pathological type or histological grade ( P>0.05). The positive expression rates of P53 protein in normal ovarian tissues, benign ovarian tumors, borderline ovarian tumors and epithelial ovarian carcinoma were 0%, 3.4%, 28.6% and 63.2%, respectively, which had a gradually rising trend with significantly difference among four groups ( P<0.05). The expression of P53 protein in borderline ovarian tumors was significantly higher than those in normal ovarian tissues and benign ovarian tumors ( P<0.05). The expression of P53 protein in epithelial ovarian carcinoma group was significantly higher than those in the rest three groups ( P<0.05). Statistical significance was found between the expression of P53 protein and histological type, differentiation, stage, lymph node metastasis ( P<0.05); But Numb expression had no correlation with age ( P>0.05). The expression of Numb protein was positive correlated with the expression of P53 protein in borderline ovarian tumors and epithelial ovarian carcinoma ( r=0.488, P<0.05; r=0.231, P<0.05). Conclusion Co-testing Numb and P53 protein might be helpful for the diagnosis and evaluation of prognosis of epithelial ovarian carcinoma and two proteins might work together in the development process of epithelial ovarian carcinoma.