Abstract: Objective：Detection of EphrinA3 expression level in epithelial ovarian cancer tissue ，preliminary to explore EphrinA3 role in ovarian cancer. Methods：Immunohistochemistry was used to detect the expression of the EphrinA3 protein. Results：Positive expression rate of EphrinA3 in ovarian cancer was 73.3%，significantly higher than that in benign ovarian tumors （20%） and normal ovaries （16.7%）；Ⅲ-Ⅳ ovarian cancer tissue EphrinA3 positive expression rate was significantly higher than Ⅰ-Ⅱ phase（83.3% vs. 33.3%，P＜0.01）；poorly differentiated ovarian carcinoma，the positive expression rate was significantly higher than in well-differentiated ovarian carcinoma （80% vs. 40%，P＜0.01）；EphrinA3 positive expression in lymph node metastasis group was significantly higher than no metastasis group（88.9% vs. 50%，P＜0.05），and regardless of the histopathological type （P＞0.05）. Conclusions：High EphrinA3 expression was in epithelial ovarian cancer，and different expression levels of EphrinA3 were different in different clinical stage and histological grade.

Key words: Ovarian neoplasms, EphrinA3, Immunohistochemistry, Genes, Tumor suppressor