Abstract： Objective To evaluate septin-9 and clusterin protein levels in the peripheral blood samples from epithelial ovarian cancer patients, and explore its clinical significance. Methods Clinical data of 200 patients in Cancer Hospital,Chinese Academy of Medical Sciences from Jan. 29, 2008 to Feb. 1,2010 were collected. The peripheral blood samples were obtained from 137 epithelial ovarian cancer patients, 12 borderline ovarian tumor patients, 10 benign ovarian tumor patients, 41 benign pelvic lesion patients and 58 healthy women. The septin-9 and clusterin protein levels in the plasma were measured by double antibody sandwich ELISA or ELISA. The clinical significance of clusterin and septin-9 in plasma was analyzed. The diagnostic efficacy of septin-9 and clusterin protein in the detection of ovarian cancer was evaluated by the area under the curve (AUC) of the receiver operating characteristic (ROC) curve. Results Double antibody sandwich ELISA showed: the mean levels of plasma septin-9 in epithelial ovarian cancer patients or benign pelvic lesion patients were significantly higher than that in healthy women detedted by double antibody sandwich ELISA (P<0.01). The mean levels of plasma septin-9 in epithelial ovarian carcinoma patients with tumor family history or distance metastasis were significantly higher than those patients without (P<0.05). While the expression level of septin-9 protein in peripheral blood of ovarian cancer patients was not related to the patient age, pathologic stage, pathologic differentiation, smoking history, treatment history (including surgery, radiotherapy and chemotherapy) and lymph node metastasis (all P>0.05). ELISA showed: the mean level of plasma clusterin in epithelial ovarian cancer patients was significantly higher than that in healthy women deteded by ELISA (P=0.021). The expression level of clusterin protein in peripheral blood of ovarian cancer patients was not related to the above clinical pathological parameters (all P>0.05). To distinguish between ovarian cancer patients and healthy women by septin-9 protein expression level in plasma, when AUC was 0.712 and cut off was 0.28, the sensitivity of detection ovarian cancer by septin-9 protein expression was 82.5%, and the specificity was 50.0%. To distinguish between ovarian cancer patients and healthy women by clusterin protein expression level in plasma, when AUC was 0.636 and cut off was 87.96 pg/L, the sensitivity of detection ovarian cancer by clusterin protein expression was 71.5%, and the specificity was 41.4%. Conclusions The expression of septin-9 and clusterin protein in peripheral blood of ovarian cancer patients is increased, especially the expression level of septin-9 protein with related to the distant metastasis. The study results shown that the detection of septin-9 and clusterin in plasma has a certain diagnosis value in ovarian cancer, which may be a potential markers for ovarian cancer.