Abstract: Objective : To investigate the expression of RhoC protein in normal ovarian tissues, benign ovarian ep-ithelial tumors, borderline malignancies and ovarian epithelial carcinoma, and to explore the correlation be-tween the expression of RhoC protein and occurrence, progression and biological behavior of ovarian epithe-lial carcinoma. Methods : The expression of RhoC protein was detected by immunohistochemistrical SPmethod in 19 samples of normal ovarian tissues, 20 samples of ovarian benign epithelial tumor, 27 samples ofovarian epithelial borderline tumor and 45 samples of ovarian epithelial carcinoma. The relationship betweenRhoC protein and pathological feature was analyzed. Results : RhoC was absent in both normal ovarian tis-sues and benign epithelial tumors. The positive rates of RhoC protein expression in borderline tumors and o-varian cancer were 25.93% and 26.67%, respectively, significantly higher than in normal ovarian tissues andbenign ovarian epithelial tumors (P<0.05). No significant difference was found in RhoC protein expression be-tween ovarian carcinoma and borderline tumors (P>0.05). The expression of RhoC protein was correlatedwith clinical stage and histological differentiation, but not associated with pathological type (P>0.05). Tissuesfrom ovarian carcinoma of late stage and poor differentiation presented with increased RhoC expression. Conclusion : RhoC protein may play an important role in the occurrence and development of ovarian cancer.The detection of RhoC protein expression may be helpful in predicting the malignant degree of ovarian tumorand its prognosis.